A practical H1 preparation guide for SME owners, directors, and finance teams — close the first half of FY 2026-27 cleanly so statutory audit season arrives without surprises.

Most SME owners think about audit preparation in May or June — when the auditor’s appointment letter arrives and the request for documents lands in the inbox. By then, the cost of preparation has already been paid in time and stress: reconstructing six months of transactions, chasing bank reconciliations for periods long closed, resolving GST mismatches that should have been caught in real time.

The businesses that sail through audit season are the ones that treat October — the halfway point of FY 2026-27 — as the first serious checkpoint. H1 (April to September 2026) is now complete. The books for six months exist, the GST returns are filed, and the compliance trail is partially laid. What happens between now and March 2027 determines how smooth the audit is — but October is the earliest point at which H1 can be reviewed, gaps identified, and corrective action taken while it still matters.

This checklist covers the eight areas that auditors examine most closely for SMEs — and specifically what you should verify now, in October, to close H1 cleanly and set up H2 correctly.

Why October Is the Right Time to Start Audit Preparation

October sits at a useful point in the financial year for three reasons:

• H1 is complete. Six months of transactions, GST filings, TDS deposits, and payroll are on record. Errors are fresh enough to correct but not so recent that the pattern is invisible.
• Q2 compliance is just closed. The September GSTR-3B — the final FY 2025-26 ITC return — was filed in October. Your FY 2025-26 GST position is now settled. Any unreconciled items from Q1 or Q2 are immediately identifiable.
• Auditors plan their schedule in November–December. Firms that approach their CA in October with organised books and a completed pre-audit checklist almost always get priority scheduling and faster turnaround than those who start the conversation in April.

What Statutory Auditors Actually Look For in SME Books

Understanding the auditor’s lens helps you prepare more efficiently. For SMEs, the areas that generate the most audit queries are predictable. They are not usually fraud — they are reconciliation gaps, classification errors, and missing documentation.

The October Pre-Audit Checklist: Eight Areas to Verify Now

Work through each area. The checklist box format is designed to be printed or used digitally. Items marked HIGH impact are the ones most likely to become audit qualifications or queries if unresolved.

What Is Different for FY 2026-27 Audit: Three Changes to Know

FY 2026-27 introduces three specific changes that affect audit preparation — beyond the usual annual compliance requirements.

1. Mandatory Audit Trail in Accounting Software

MCA requires all companies using accounting software to maintain an audit trail — an edit log that records every change to every transaction, including who made the change and when. The audit trail must be enabled throughout the financial year and cannot be disabled even temporarily.

What to check now: Log in to your accounting software (Tally Prime, Busy, Zoho Books, or others) and verify that the audit trail/edit log feature is active. If it was disabled at any point in H1, document the reason — auditors are specifically required to report on this under CARO 2020. A disabled audit trail is now a reportable matter.

2. Income Tax Act 2025 Transition Documentation

The Income Tax Act, 2025 came into effect from 1 April 2026. All TDS, advance tax, and income tax compliance for FY 2026-27 (Tax Year 2026-27) must reference the new Act’s section numbers. Tax audits for FY 2026-27 will use updated Form 3CD templates with new section references.

What to check now: Verify that your accounting software and TDS return filing software have been updated to use the new section numbering under the Income Tax Act, 2025. For H1 TDS returns (Q1 and Q2, already filed), verify that the section references used were correct. If discrepancies exist, a revised return may be necessary before the tax audit.

3. ICAI 60-Audit Limit per Partner

From April 2026, ICAI has implemented a limit of 60 statutory audits per partner. This has led to significant reshuffling of audit assignments across CA firms, with many partners at larger firms relinquishing assignments to comply with the limit.

What to check now: Confirm with your CA firm that the partner assigned to your audit has not exceeded the 60-audit limit and that your assignment has not been transferred to another partner without your knowledge. Under the Companies Act, a change of auditor requires specific board approval and ROC intimation (Form ADT-1). Informal partner reshuffling without documentation is a compliance gap.

The 6 Most Common Audit Findings for SMEs — and How to Prevent Them

These are the observations that appear in SME audit reports most frequently. Each one is preventable with the checklist above.

1. GST-books revenue mismatch without documentation

Auditors cross-check GSTR-1 turnover with P&L revenue. Every difference must be explained — exempt supplies, advance receipts, branch transfers, timing differences. Businesses that cannot explain the difference receive a qualified observation. Prevention: prepare a written GST-books reconciliation note for each quarter and file it with the working papers.

2. Bank reconciliations with stale items

Uncleared cheques older than 90 days, unexplained credits in bank statements, and deposits not matched to specific transactions are the most common bank-related findings. Prevention: review all bank reconciliations monthly and explain every item older than 30 days in writing at the time it is identified — not during the audit.

3. TDS defaults or mismatches

Auditors run a Form 168(earlier 26AS)reconciliation against your books. Differences where TDS was deducted from your payments but not deposited by the deductor, or where you deducted TDS but deposited it late, are both flagged. Prevention: monthly TDS tracking, on-time deposits, and TRACES reconciliation every quarter.

4. Related party transactions without board approval

All contracts with related parties — including director remuneration above the approved limit, inter-company purchases, and director facility usage — require specific board approval and in many cases shareholder approval. Missing documentation creates both audit qualifications and Companies Act compliance exposure. Prevention: maintain a running RPT register with approvals as transactions occur.

5. Fixed assets not physically verified

Auditors ask for physical verification reports of fixed assets — particularly for IT assets, office furniture, and vehicles. Many SMEs have assets fully depreciated but still in use (which is fine), and assets shown in the register that have been disposed of without recording. Prevention: conduct a half-yearly physical verification and update the register by October each year.

6. Year-end provisions without adequate support

Large provisions booked in March (bonus, leave encashment, gratuity, doubtful debts) without any supporting calculation or approval attract audit scrutiny. Provisions that suddenly appear in the last month of the year appear to be income-smoothing rather than genuine accruals. Prevention: book provisions quarterly with supporting calculations, not as a year-end exercise.

Planning for GSTR-9 and GSTR-9C: The Annual GST Return

While GSTR-9 is not due until 31 December 2026 for FY 2025-26, preparing for it in October is strategically sound — because GSTR-9 draws on the same underlying data that drives audit preparation.

What GSTR-9 requires: Annual summary of all outward and inward supplies, ITC availed and reversed, tax paid, and demand and refund details for FY 2025-26. It reconciles your 12 months of GSTR-3B filings and GSTR-1 data.

GSTR-9C (for turnover above ₹5 crore): A self-certified reconciliation statement comparing audited financial statements with GSTR-9 data. This document requires the figures from your statutory audit — which means GSTR-9C cannot be prepared until the audit is complete.

October action: Extract a consolidated H1 FY 2025-26 GST summary (April 2025–September 2025) and begin reconciling it with your H1 books. The full FY 2025-26 GSTR-9 preparation will be easier if this work is done now while the transactions are relatively recent.

Setting Up H2 (October–March 2027) Correctly From Day One

The October checklist covers H1. But October is also the start of H2 — and the disciplines you establish now determine how smooth the second half of the year is.

• Implement monthly bank reconciliations as a process, not a catch-up exercise. Assign a specific person and a specific date (e.g., 5th of each month) for bank reconciliation. The H1 backlog is the last time this should be a catch-up exercise.
• Set a calendar reminder for TDS deposits on the 6th of each month. The deadline is the 7th. A 6th reminder gives one working day of buffer for portal issues and bank processing.
• Book provisions quarterly, not annually. Bonus, leave encashment, audit fees, and doubtful debt provisions booked quarterly make the audit far cleaner than 12 months of unexpensed liabilities booked in March.
• Review the fixed asset register after every significant purchase. Add new assets immediately, not at year-end. Depreciation should be calculated on the actual purchase date, not approximated at March.
• Maintain a running related party transaction log. As RPTs occur, log them with the approval reference, nature of transaction, amount, and pricing basis. This takes 10 minutes per transaction and saves 3–4 hours of audit query resolution per RPT.

Related Reading

→ October 2026 GST & TDS Filing Deadlines: Compliance Calendar

→ Quarterly Review: How to Reconcile GST & Books Before Q2 Ends

→ 10 Signs Your Growing Business Needs a Virtual CFO Right Now

→ The Simple SME Accounting Checklist for a Better 2026

The post How to Avoid Audit Preparation Mistakes in FY 2026–27 first appeared on CPC Services Pvt. Ltd..

Every deadline your business needs to hit in October 2026 — with the one date that closes the door on FY 2025-26 ITC permanently.

October 2026 is a month with consequences. The 20 October deadline for GSTR-3B is the final date to claim any unclaimed input tax credit from FY 2025-26. Miss it and that credit is gone permanently — no extension, no reversal, no recovery. The 31 October deadline brings the ITR for audit cases, Q2 TDS return, and ITR for domestic companies all due on the same day.

For QRMP taxpayers, October is also the quarter-end return month — the Q2 GSTR-3B (covering July, August, September) is due 22 or 24 October. And for monthly filers, the routine September GST cycle continues: GSTR-1 by 11 October, GSTR-3B by 20 October.

This blog covers every October 2026 compliance deadline, what each involves, what it costs to miss, and the specific actions to take before the month ends.

All October 2026 Compliance Deadlines at a Glance

The ITC Lapse Deadline: What Happens on 20 October 2026

This is the deadline that no other compliance calendar article typically explains with the clarity it deserves. So we will.

The rule: Under Section 16(4) of the CGST Act, input tax credit for FY 2025-26 can only be claimed until the earlier of the due date for the September 2026 GSTR-3B return, or the date of filing the annual GSTR-9 return for FY 2025-26.

The practical deadline: For monthly filers, the due date for September 2026 GSTR-3B is 20 October 2026. For QRMP filers, it is 22 or 24 October 2026.

What this means: Any purchase invoice from FY 2025-26 (April 2025 to March 2026) that has not been claimed as ITC in any GSTR-3B up to and including the September 2026 return is permanently gone after 20 October. The credit cannot be reclaimed, carried forward, or refunded.

TDS Compliance in October 2026

TDS Deposit — 7 October 2026

TDS deducted from all payments made in September 2026 must be deposited by 7 October. This includes salary TDS, contractor TDS, professional fee TDS, rent TDS, and any other payment where TDS applies under the Income Tax Act, 2025 (Section 393).

Section reference reminder: All TDS on payments made after 1 April 2026 is governed by Section 393 of the Income Tax Act, 2025. Challans and TDS returns must quote the new section references — not the old 194C, 194J, 194H etc. If your accounting software has not been updated, portal validation may fail.

Q2 TDS Return — 31 October 2026

The quarterly TDS return for July–September 2026 (Q2 of Tax Year 2026-27) must be filed by 31 October 2026. This is separate from the monthly TDS deposit obligation — the return is an independent filing that reports all deductions made during the quarter.

Key forms:

• Form 138: Salary TDS — employer deducting from employee salaries across all designations and salary structures
• Form 140: Non-salary TDS to residents — contractors, professionals, rent, interest, commission
• Form 143: TDS on payments to non-residents and foreign companies

What the Q2 return must reflect: All TDS deducted in July, August, and September 2026. All challans deposited for those months (typically by 7 August, 7 September, and 7 October). Any corrections to Q1 (April–June) TDS returns should be filed as revised returns separately — not mixed into Q2.

ITR Filing Deadlines in October 2026

ITR for Audit Cases — 31 October 2026

Businesses and professionals whose accounts are required to be audited under Section 44AB of the Income Tax Act, 1961 (applicable to FY 2025-26) must file their ITR by 31 October 2026. The tax audit report (Form 3CA/3CB/3CD) must have been uploaded by 30 September 2026.

Who this covers: 

• Business taxpayers with turnover above ₹1 crore (₹10 crore if cash transactions are below 5% of total)
• Professional taxpayers with gross receipts above ₹50 lakh (₹75 lakh under presumptive scheme if opted out)
• Any taxpayer who has triggered audit under other provisions (Section 44AD opted out in a previous year but income is below 8%/6%)

For directors and partners: If the company or firm requires an audit, the director or partner's personal ITR — if linked to the company's financials — may also have an October 31 deadline rather than the August 31 deadline. Verify with your CA which deadline applies to your personal return.

ITR for Domestic Companies — 31 October 2026

All domestic companies (private limited, public limited, OPC) must file ITR-6 for FY 2025-26 by 31 October 2026. This includes companies whose turnover is below the audit threshold — the company ITR deadline is October 31 regardless of whether a tax audit applies.

October Cash Flow Planning: Sequencing Your Compliance Obligations

October’s obligations are spread across the month but require planning from the first week. Here is the sequenced action plan:

What Each Missed Deadline Costs in October

October Has Deadlines That Cannot Be Extended. Let’s Make Sure You Hit Every One.

Related Reading

→ September 2026 GST, TDS & Advance Tax Calendar: Filing Made Simple

→ July 2026 GST & TDS Due Dates: Don’t Miss These Compliance Deadlines

→ Quarterly Review: How to Reconcile GST & Books Before Q2 Ends

→ Year-End Audit Preparation Checklist for Businesses (FY 2026-27)

The post What You Need to Know: October 2026 GST & TDS Filing Deadlines first appeared on CPC Services Pvt. Ltd..

A practical guide for SME owners, business directors, and individuals — understand every common notice type, what triggered it, your deadline to respond, and when to handle it yourself vs. when to involve a professional.

Receiving an Income Tax Department notice is no longer a rare event reserved for large corporations or suspected evaders. With the introduction of the Annual Information Statement (AIS), automated data matching between GST returns and ITRs, SFT (Statement of Financial Transactions) reporting from banks and registrars, and faceless assessment infrastructure — the department now has more data about your financial activities than ever before.

Most notices are not accusatory. Many are routine. A Section 143(1) intimation is sent to virtually every taxpayer after ITR processing and requires no action in most cases. But some notices are serious — and every single one has a deadline. Ignoring a notice, regardless of its type or apparent severity, is the one response that is never acceptable.

This blog covers the seven most common notice types an SME owner, director, or individual taxpayer is likely to receive — what each means, why it was issued, your response deadline, what to do, and whether you need professional help.

Notice Severity at a Glance

Not all notices require the same level of concern or the same response. Here is how to read the severity of a notice before you do anything else:

How to Check If You Have a Pending Notice

All Income Tax Department notices are issued electronically and uploaded to the e-filing portal. No notice is valid unless it has a Document Identification Number (DIN) and appears in your portal account.

Steps to check for pending notices:

• Log in to incometax.gov.in with your PAN and password
• Go to Pending Actions → e-Proceedings on the dashboard
• Any pending notices, show-cause communications, or demand notices will appear here with the section reference and response deadline
• Check your registered email — notices are also sent to the email ID linked to your PAN on the portal
• For demand notices under Section 156, also check the ‘Outstanding Demand’ section under ‘e-File → Response to Outstanding Demand’

The 7 Most Common Income Tax Notices — Explained

5 Universal Response Principles for Any Income Tax Notice

Regardless of which notice you receive, these five principles apply to every response.

1. Read the notice before doing anything else

The section reference on the notice tells you everything — what it is, how serious it is, and what your deadline is. Read the full notice PDF (download it from the portal) before taking any action. Many notices that seem alarming are routine intimations requiring no response. Many that seem routine contain a demand that must be paid within 30 days. Read before you react.

2. Authenticate the notice on the portal

Every valid notice has a Document Identification Number (DIN) issued by the Income Tax Department. Log in to incometax.gov.in → Verify Notice/Order → Enter the DIN to confirm authenticity. Fraudulent notices are common — particularly via email or WhatsApp — claiming to be from the Income Tax Department. If the DIN is not valid on the portal, the notice is not genuine.

3. Respond only to what is asked — no more

Over-disclosure is one of the most common mistakes taxpayers make. If a 142(1) notice asks for bank statements for one account, provide those statements for the period requested — not all accounts, not all years. If a 143(2) notice lists three specific issues, address those three issues. Volunteering additional information can expand the scope of the assessment and create new issues that were not originally under scrutiny.

4. Respond on the portal — not by email or post

All responses to income tax notices must be submitted through the e-Proceedings module on incometax.gov.in. Emailing or posting documents to an ITO does not constitute a valid response under the faceless assessment system. Always download and save the acknowledgement with the Transaction ID after submitting your response — it is your proof of compliance.

5. Never miss the response deadline

Every notice carries a specific deadline — 15 days for Section 139(9), 30 days for Section 143(1) demands, 7 days (extendable) for Section 148A(b) show-cause. Missing these deadlines converts a manageable situation into a much worse one. If you need more time, apply for an adjournment from within the e-Proceedings module before the deadline expires — most AOs grant one adjournment for reasonable cause.

Why Income Tax Notices Are Increasing — The Data Behind It

The increase in income tax notices is not arbitrary. It is a direct consequence of the Income Tax Department’s investment in data infrastructure over the last five years. Understanding what data they have helps you understand why you received a notice — and how to prevent the next one.

What the Income Tax Department Now Receives Automatically

• Annual Information Statement (AIS): Aggregates data from banks (savings interest, FD interest, rent paid, large withdrawals), mutual fund houses (redemptions, dividends), SEBI (stock transactions), property registrars (property purchases and sales), GST network (turnover), and 50+ other sources. Everything in your AIS is cross-checked against your ITR.
• Statement of Financial Transactions (SFT): Banks report cash deposits above ₹10 lakh, credit card payments above ₹1 lakh per month, property purchases above ₹30 lakh, mutual fund investments above ₹10 lakh, and more. All of this flows automatically into your AIS.
• GST-ITR matching: GSTN and Income Tax share data. If your GST turnover is significantly different from your ITR income without a clear explanation (exports, exempt supplies, advance tax timing), a mismatch flag is raised.
• TDS/TCS data: All TDS deducted and deposited is reflected in Form 26AS and AIS. If TDS appears on a rental payment received but no rental income is declared, the system flags it.
• High-value transaction alerts: Property registrars report all property transactions to the IT department. If you buy a property for ₹80 lakh but declare income of ₹8 lakh, the department has grounds for a Section 148 notice.

When to Handle a Notice Yourself vs. When to Involve a CA

The answer depends on the notice type, the amount in dispute, and your comfort with the portal and tax law.

How to Prevent Income Tax Notices: A Pre-Filing Checklist

Prevention is always cheaper than resolution. These are the steps that eliminate the most common notice triggers before your ITR is filed.

• Download AIS and Form 26AS immediately before filing — not weeks earlier. Both documents are dynamic and updated as deductors file TDS returns and financial institutions report transactions. The version from two weeks ago may not reflect a recently deposited TDS or a newly reported transaction.
• Reconcile every entry in AIS with your return before filing. For every income item in AIS — FD interest, rental income, capital gains, dividend — verify it is correctly reflected in your ITR. If an AIS entry is incorrect, use the AIS feedback facility to flag it before filing.
• Check that GST turnover and ITR income are reconciled and explainable. If there is a difference, prepare a written reconciliation note with specific reasons — export turnover, advance receipts, exempt supplies, etc. This document should be ready before filing, not only when a notice arrives.
• Use the correct ITR form. The most avoidable notice is Section 139(9) — defective return — caused by filing the wrong form. Verify your form selection against your income sources every year, not just in the year you first filed.
• File on time. Many notices arise from late filing — because the old tax regime option is lost, carry-forward losses are forfeited, or the department flags late filers for additional scrutiny. The 31 July and 31 August deadlines exist for good reason.

Received a Notice? Don’t Ignore It. Don’t Panic. Call Us.

Related Reading

→ September 2026 GST, TDS & Advance Tax Calendar: Filing Made Simple

→ ITR Filing 2026: Step-by-Step Guide + Common Mistakes to Avoid

→ Quarterly Review: How to Reconcile GST & Books Before Q2 Ends

→ 10 Signs Your Growing Business Needs a Virtual CFO Right Now

The post How to Avoid Costly Mistakes With Income Tax Notices first appeared on CPC Services Pvt. Ltd..

A step-by-step guide for salaried employees, freelancers, business owners, and SME directors — calculate your Q2 advance tax instalment accurately and pay before the deadline to avoid compounding interest.

Most taxpayers in India know about the September 15 advance tax deadline. Far fewer know exactly how to calculate the correct amount — or understand why getting it wrong in September is more expensive than missing any other instalment during the year.

The second advance tax instalment requires a cumulative payment of 45% of your estimated annual tax by 15 September. That means it is not just the tax on Q2 income. It accounts for Q1 income too, less whatever you paid in June. If you underpaid in June, September catches that up — with interest running from June 15, not from September 15.

This guide gives you the calculation framework, three worked examples by taxpayer type, the exact payment steps on the Income Tax portal, and the interest calculation for anyone who has already missed the June instalment.

Who Must Pay Advance Tax?

Advance tax applies broadly — not just to business owners. Here is the complete picture:

You must pay advance tax if:

• Your estimated total income tax for FY 2026-27 exceeds ₹10,000 after TDS. This includes TDS deducted by your employer, banks, tenants, and any other deductors.
• You have income that is not covered by TDS — rental income, business profit, freelance income, FD interest, dividend income, or capital gains.
• You are a salaried employee who switched jobs during the year and the new employer is not accounting for the previous employer’s TDS.
• You have made capital gains in FY 2026-27 that were not anticipated when June’s advance tax was paid.

You are exempt from advance tax if:

• You are a senior citizen (60 years or above) with no income from business or profession — fully exempt regardless of income level.
• You are a small business or professional under presumptive taxation (Section 44AD or 44ADA). You can pay 100% of advance tax as a single instalment by 15 March 2027. No quarterly payments required.
• Your entire tax liability is covered by employer TDS. If TDS deducted by your employer equals or exceeds your full tax, no separate advance tax payment is needed.

The Four-Instalment Schedule for FY 2026-27

Advance tax is paid in four cumulative instalments. The percentages are cumulative — each instalment includes the total paid so far, not just the current quarter’s share.

How to Calculate Your September 15 Advance Tax Payment

Follow these six steps to calculate exactly how much to pay by 15 September 2026.

1. Estimate your total income for FY 2026-27

Add up all income you expect to earn between April 2026 and March 2027:

• Salary: Your expected gross salary for the full year (not just April–September)
• Business/professional income: Estimated net profit for the full year based on Q1 actual and projected Q2–Q4
• Rental income: Annual rental receipts, net of municipal taxes paid
• Capital gains: Any gains already realized (shares, mutual funds, property) plus any anticipated before March 2027
• Interest income: FD interest, savings account interest, bond interest for the full year

2. Deduct eligible deductions and exemptions

Under whichever regime you have chosen for FY 2026-27:

New regime: Deduct ₹75,000 standard deduction (salaried), employer NPS contribution (Section 80CCD(2)), and any other specific exemptions available under the new regime.

Old regime: Deduct all eligible amounts — 80C (up to ₹1.5 lakh), 80D, HRA exemption, home loan interest (Section 24b, up to ₹2 lakh for self-occupied), NPS (80CCD(1B)), and any other applicable deductions.

Compute your taxable income.

3. Calculate the tax on taxable income

Apply the appropriate tax slabs for FY 2026-27 to your estimated taxable income:

New regime slabs: Nil up to ₹4L | 5% on ₹4L–₹8L | 10% on ₹8L–₹12L | 15% on ₹12L–₹16L | 20% on ₹16L–₹20L | 25% on ₹20L–₹24L | 30% above ₹24L

Old regime slabs: Nil up to ₹2.5L | 5% on ₹2.5L–₹5L | 20% on ₹5L–₹10L | 30% above ₹10L

Add 4% health and education cess on the total tax. Add surcharge if income exceeds ₹50 lakh.

4. Subtract TDS already deducted or expected for the full year

TDS is a credit against your advance tax obligation. Deduct:

• Employer TDS: Projected TDS from Form 16 for the full year (ask your employer for the projected TDS figure)
• Bank TDS (Section 194A): TDS on FD interest, typically 10% if PAN is provided
• TDS on rent received (Section 194I): If your tenant deducts TDS on rent paid to you
• TCS received: Any TCS collected by sellers from whom you purchased goods

This gives you your net advance tax liability for the year. If this figure is below ₹10,000, no advance tax is required.

5. Calculate what you must pay by 15 September

Your September payment = 45% of net advance tax liability − what you already paid in June.

Formula: September payment = (Net annual tax liability × 45%) − June payment made

• If you underpaid in June: The shortfall from June also attracts interest from 15 June. You should make up the June shortfall in September to stop the interest from compounding further.
• If you overpaid in June: The excess counts toward the 45% requirement — reduce September payment accordingly. No refund for over payment at instalment stage; excess is adjusted at ITR filing.

6. Pay online via Income Tax e-filing portal

Go to incometax.gov.in → e-File → e-Pay Tax → New Payment → Income Tax. Select:

• Tax Year: 2026-27
• Type of Payment — Minor Head: 100 — Advance Tax
• Assessment Year: 2027-28

Enter the tax amount under the relevant heads (income tax, surcharge if applicable, cess). Choose your payment method (net banking, UPI, debit card, NEFT/RTGS). Download and save the challan immediately after payment — note the CIN (Challan Identification Number). You will need it for ITR filing.

Three Worked Examples: Calculate Your September Payment

Use these examples as templates. Replace the figures with your own estimated income and deductions.

Example 1: Rajan, Salaried Employee with Rental Income — ₹18 lakh salary + ₹4.8 lakh annual rent

Rajan’s total tax is modest because employer TDS covers most of his liability. His September payment is under ₹12,000 — but if he skips it, interest at 1% per month runs on the ₹11,937 shortfall from September 15 onwards.

Example 2: Meera, Freelance Consultant — Estimated ₹28 lakh net professional income

Meera underpaid in June by ₹4,260. That shortfall has been attracting 1% per month interest since 15 June — approximately ₹85 in interest for the June-to-September period. Her September payment of ₹1,02,780 brings her to the 45% cumulative threshold and stops the June shortfall interest from compounding.

Example 3: Ashok, SME Owner — Manufacturing business, estimated ₹50 lakh profit

Ashok’s surcharge (10% on income between ₹50L and ₹1 crore) adds ₹1.08 lakh to his tax. Many business owners miss the surcharge in their advance tax estimate — and then face a ₹10,000+ shortfall interest at year-end. Always check if your income crosses ₹50 lakh, ₹1 crore, or ₹2 crore surcharge thresholds.

Interest Calculation: What It Costs to Underpay

Missing or underpaying the September advance tax instalment triggers interest under Section 234C of the Income Tax Act, 2025 (formerly Section 234C of the old Act). Here is how to calculate it:

Interest Under Section 234C (for Instalment Shortfall)

Formula: Interest = Shortfall from required cumulative amount × 1% × number of months

For the September instalment: If by 15 September you have paid less than 45% of your annual tax, interest runs at 1% per month on the shortfall — for 3 months (from 15 September to 15 December, when the next instalment is due). If the shortfall is still not covered by December, interest continues.

For the June instalment shortfall carried into September: If you underpaid in June, the shortfall attracted interest from 15 June. If you pay the outstanding in September, interest runs for 3 months (June to September). Each month is counted as a full month — even if you pay on 16 September, that is a full additional month.

Already Missed the June Instalment? What to Do Before September 15

If you paid nothing in June — or paid less than 15% — the September instalment is your opportunity to correct the position. Here is the practical approach:

If you paid nothing in June:

You need to catch up to the 45% cumulative threshold by September 15. Pay the full 45% in one payment. Interest under Section 234C for the June shortfall has already accrued for 3 months (June 15 to September 15) — this cannot be avoided. But paying the full 45% now stops further interest from the September instalment.

Interest already owed on June shortfall: 15% of annual tax × 1% × 3 months. For a taxpayer with ₹5 lakh annual tax liability, this is ₹5 lakh × 15% × 1% × 3 = ₹2,250. This interest is not paid separately — it is accounted for when the ITR is filed and assessed.

If you paid some but below the 15% threshold in June:

Interest under 234C runs on the portion of the shortfall only. In September, pay enough to reach the 45% cumulative threshold. The June shortfall interest is calculated and added at assessment time — you do not need to pay it separately now.

5 Common Advance Tax Mistakes — and How to Avoid Them

1. Estimating only April–September income instead of the full year

Advance tax is based on your estimated total income for FY 2026-27 (April 2026 to March 2027). If you estimate only the first half, you understate your liability — and the December and March instalments become very large, or interest under Section 234B accrues at year-end. Always project the full year’s income, even if the second half is uncertain. Use a conservative but realistic estimate.

2. Forgetting to include capital gains in the estimate

Capital gains from selling shares, mutual funds, or property are part of your taxable income and affect advance tax liability. Many taxpayers who sell assets mid-year forget to include the gains in their advance tax estimate. The result: a significant shortfall discovered only at ITR filing time, with Section 234B interest running from April of the assessment year.

3. Not accounting for surcharge at income above ₹50 lakh

The tax calculation seems correct — until income crosses ₹50 lakh and a 10% surcharge applies. For a taxpayer with ₹55 lakh taxable income under the new regime, the surcharge adds approximately ₹30,000–₹35,000 in additional tax. If the advance tax estimate was made without surcharge, the shortfall attracts full Section 234C interest. Always check if your income crosses the ₹50 lakh, ₹1 crore, or ₹2 crore surcharge thresholds.

4. Using old Act section numbers when paying via portal

From FY 2026-27, advance tax payments are governed by the Income Tax Act, 2025. When paying on the portal, select Tax Year 2026-27 (not Assessment Year 2026-27 — that would apply to FY 2025-26 payments). A payment credited to the wrong tax year does not count as advance tax for the current year and creates a mismatch at assessment.

5. Paying on 16 September instead of 15 September

Interest is calculated in full months. If you pay on 16 September 2026 instead of 15 September, the month of September counts as a complete month for Section 234C purposes. For a taxpayer with a ₹2 lakh shortfall, this one-day delay costs ₹2,000 in additional interest. Mark 13 September as your internal deadline — that gives two working days buffer for portal glitches and bank processing.

Pay the Right Amount. Pay on Time. Pay Once.

Related Reading

• September 2026 GST, TDS & Advance Tax Calendar: Filing Made Simple
• New vs Old Tax Regime FY 2026-27: Which One Should You Choose?
• ITR Filing 2026: Step-by-Step Guide + Common Mistakes to Avoid
• 10 Signs Your Growing Business Needs a Virtual CFO Right Now

The post Advance Tax September 15: How to Avoid Common Costly Mistakes first appeared on CPC Services Pvt. Ltd..

Every deadline your business needs to hit in September 2026 — explained simply, with what each filing involves and exactly what it costs to miss it.

September is the most compliance-intensive month of the financial year for Indian businesses. Three major obligations converge in a single 30-day window: GST return filings for August, the second installment of advance tax for FY 2026-27, and the monthly TDS deposit cycle. Most crucial is furnishing of Audit Report under section 44AB (of Income-tax Act, 1961 as applicable for FY 2025-2026) on or before due date i.e. 30th September 2026. A single day delay may cost a heavy penalty which may extend to 1.50 Lakh.

For businesses with turnover above ₹5 crore, GSTR-3B is due on 20 September. The advance tax second instalment — 45% of estimated annual liability, cumulative — is due on 15 September. The TDS deposit for August deductions is due on 7 September. If your business falls under all three, you have a significant cash flow obligation in a single fortnight.

This blog gives you every deadline for September 2026, explains what each involves, and gives you the penalty calculation for any you miss — so you can prioritize correctly and avoid paying a rupee more than you owe.

All September 2026 Compliance Deadlines at a Glance

This is your complete compliance calendar for September 2026. Dates shaded in blue are GST deadlines; those in green are income tax and TDS deadlines.

TDS Compliance in September 2026

TDS Deposit — 7 September 2026

Any TDS deducted from payments made in August 2026 must be deposited with the government by 7 September 2026. This applies to salary TDS (deducted monthly from employee salaries), TDS on contractor payments, professional fees, rent, interest, commission, and any other payment where TDS is applicable under the Income Tax Act, 2025.

Governing law: Since all August 2026 payments occur after 1 April 2026, TDS is now governed by Section 393 of the Income Tax Act, 2025 (not Sections 194C, 194J, 194H etc. of the old Act). When depositing TDS, ensure your challan quotes the correct new section reference. Portal validation may fail if old Act section numbers are used for post-March 2026 transactions.

Advance Tax: The 15 September Deadline Explained

The 15 September deadline is the second of four advance tax installments for FY 2026-27. It is also the most misunderstood — because the percentage required is cumulative, not just for the quarter.

What ‘cumulative 45%’ means in practice: If your estimated annual tax liability is ₹3 lakh, you must have paid a total of ₹1,35,000 by 15 September — including whatever you paid on 15 June. If you paid ₹30,000 in June (10% — below the required 15%), you need to pay at least ₹1,05,000 in September to reach the 45% cumulative threshold. The shortfall from June also attracts interest.

Who is exempt from advance tax:

• Senior citizens (above 60 years) with no business or professional income — fully exempt from advance tax
• Presumptive taxation taxpayers under Section 44AD and 44ADA (small businesses and professionals with turnover/receipts below the prescribed limits) — can pay 100% of advance tax as a single instalment by 15 March 2027
• Salaried individuals whose entire tax liability is covered by employer TDS — no advance tax required

GST Filing Deadlines in September 2026

GSTR-1: Outward Supply Return — 11 September 2026

Monthly GST filers must report all B2B and B2C invoices issued in August 2026 by 11 September. With GSTR-3B hard-locked since July 2025, GSTR-1 accuracy is more important than ever — errors cannot be corrected directly in GSTR-3B and must go through GSTR-1A before GSTR-3B is filed.

• Critical for September specifically: Any FY 2025-26 invoice that has not yet been reported or was reported with errors must be amended in September’s GSTR-1 (Table 9A). The November 2025 amendment cut-off has passed — September is the last practical window to capture FY 2025-26 output corrections before year-end.
• QRMP filers: September is the last month of Q2 (July–September). Your quarterly GSTR-1 for Q2 is not due until 13 October 2026. However, if you have B2B buyers whose ITC depends on seeing your August invoices in their September GSTR-2B, use the Invoice Furnishing Facility (IFF) before 13 September to upload those invoices for the month.

GSTR-3B: Summary Return + Tax Payment — 20 September 2026

GSTR-3B for August 2026 is due 20 September for monthly filers. This is simultaneously the most important deadline this month and the one with the most cash flow impact — particularly for businesses that also owe advance tax by 15 September.

• September-specific cash flow alert: If you owe both advance tax (15 Sep) and GSTR-3B tax payment (20 Sep), plan your liquidity carefully. Both are cash outflows within 5 days of each other. For a business with ₹50 lakh monthly GST turnover, the GSTR-3B net tax payment alone can be ₹3–8 lakh. Add the advance tax instalment and the combined cash requirement in one fortnight is material.

PMT-06: Monthly GST Payment for QRMP Taxpayers — 25 September 2026

QRMP taxpayers file GST returns quarterly but pay tax monthly. The August 2026 tax payment via Form PMT-06 is due by 25 September. The amount can be calculated using either the Fixed Sum Method (35% of previous quarter’s GSTR-3B tax) or the Self-Assessment Method (based on actual August ITC and liability). If August was a high-revenue month compared to last quarter, the Fixed Sum Method may underpay — use the Self-Assessment Method for accuracy.

Tax Audit Report Deadline — 30 September 2026

Businesses and professionals whose books are required to be audited under Section 44AB must have their Chartered Accountant sign and upload the tax audit report (Form 3CD/3CA/3CB) by 30 September 2026. The ITR filing deadline for audit cases is 31 October 2026 — which is directly dependent on the audit report being completed first.

Who this applies to:

Businesses with turnover above ₹1 crore (₹10 crore if cash transactions are below 5%), and professionals with gross receipts above ₹50 lakh (₹75 lakh under presumptive scheme). Directors of private limited companies and partners of auditable firms also need to ensure the entity-level audit is complete before their personal ITR deadline.

What Each Missed Deadline Costs You: September Edition

September’s deadlines are more expensive to miss than most months — because three of them carry compounding consequences.

Planning Your September Cash Flow: The Fortnight That Matters

For any SME owner juggling GST, TDS, and advance tax simultaneously, September requires deliberate cash flow planning. Here is the sequence of outflows and what to prepare:

September Has Three Deadlines in One Fortnight. Let’s Make Sure You Hit All of Them.

Related Reading

→ July 2026 GST & TDS Due Dates: Don’t Miss These Compliance Deadlines

→ Advance Tax September 15 Deadline: How to Calculate & Pay Correctly

→ Quarterly Review: How to Reconcile GST & Books Before Q2 Ends

→ 10 Signs Your Growing Business Needs a Virtual CFO Right Now

The post September 2026 GST, TDS & Advance Tax Calendar: What You Need to Know for Simple Filing first appeared on CPC Services Pvt. Ltd..

A decision-first guide for salaried employees, business owners, and professionals — with real numbers, a clear breakeven framework, and the one deadline most people miss.

Every year, millions of Indian taxpayers make the same mistake: they let the default decide for them. The new tax regime has been the default since FY 2023-24 — which means if you did not explicitly choose the old regime when filing your ITR or declaring to your employer, you were automatically placed in the new one, whether or not it was better for you.

For FY 2026-27, the choice matters more than ever. Budget 2026 confirmed no changes to the tax slabs — the same structure that applied in FY 2025-26 continues. That means the numbers in this guide are the numbers you plan with. The ₹12 lakh zero-tax threshold under the new regime stays. The deductions under the old regime stay. The decision framework is the same — and August is exactly the right time to make it for the full year ahead, before advance tax planning begins.

This guide gives you the framework, the numbers, and the decision — by income level and income type — so you can plan FY 2026-27 with certainty rather than guesswork.

What Changed for FY 2026-27 — And What Stayed the Same

Budget 2026 (presented February 2026) made no changes to income tax slab rates under either regime. The structure introduced in Budget 2025 — including the ₹12 lakh zero-tax threshold — continues unchanged for FY 2026-27 (Tax Year 2026-27 under the new Income Tax Act, 2025).

What stayed the same:

• New regime remains the default — you must actively opt for the old regime
• Tax slabs, rates, and Section 87A rebate are unchanged under both regimes
• Standard deduction: ₹75,000 under new regime, ₹50,000 under old regime for salaried individuals
• Section 87A rebate: ₹60,000 (new regime, income up to ₹12 lakh) and ₹12,500 (old regime, income up to ₹5 lakh)
• Surcharge cap: 25% maximum under new regime vs up to 37% under old regime for very high incomes

What changed in Budget 2026 (relevant to tax planning):

• Revised return deadline extended to 31 March 2027 (was 31 December) — more time to correct ITR errors
• TDS/TCS now governed by Income Tax Act, 2025 for transactions from 1 April 2026 onwards
• ITR-3 and ITR-4 (non-audit) get extended deadline to 31 August — more time for business filers

Tax Slab Comparison: New Regime vs Old Regime FY 2026-27

New Tax Regime Slabs (Default)

Applies to all taxpayers regardless of age. Standard deduction of ₹75,000 for salaried individuals. No other deductions or exemptions except employer NPS contribution (Section 80CCD(2)) and a few specific allowances.

CPC INSIGHT — 

Section 87A Rebate (New Regime)

The slab table above shows tax being charged from ₹4,00,001 onward — but that is not what most people actually pay.

Rebate: up to ₹60,000 under Section 87A.

If your taxable income does not exceed ₹12,00,000, the rebate cancels out the tax calculated from the slabs entirely — your final tax payable is zero.

For salaried individuals, this means gross salary up to ₹12,75,000 (after the ₹75,000 standard deduction) results in zero tax payable.

In short: Tax is calculated first using the slabs, then the rebate wipes it out below the ₹12 lakh threshold. The slab rates in the 5–10% range are not what a taxpayer under ₹12 lakh actually pays.

Surcharge: Capped at 25% for income above ₹2 crore under the new regime.

Old Tax Regime Slabs (Optional — must be actively chosen)

Allows deductions under Section 80C, 80D, 24(b) (home loan interest), HRA, LTA, and 70+ other provisions. Standard deduction of ₹50,000 for salaried individuals. Different exemption limits by age.

CPC INSIGHT 

Section 87A Rebate (Old Regime)

Rebate: Up to ₹12,500 under Section 87A.

If taxable income (after all deductions claimed) does not exceed ₹5,00,000, this rebate cancels out the tax calculated from the slabs — final tax payable is zero.

Bottom line, as confirmed for this guide: from AY 2026-27, there is zero tax up to an income of ₹12 lakh under the New Regime, and up to ₹5 lakh under the Old Regime — in both cases because the rebate, not the slab structure, is what brings the final bill to nil.

Surcharge: Up to 37% for income above ₹5 crore — highest surcharge unchanged.

Side-by-Side Tax Comparison at Key Income Levels

This table shows actual tax outgo under each regime at common income points, assuming salaried income with standard deduction applied, and no additional deductions under the old regime. Use this as a starting baseline — your actual tax depends on your specific deduction profile.

Note: Tax amounts include 4% health and education cess. Surcharge not applied (income assumed below ₹50 lakh). Old regime figures assume no deductions — add your actual deductions to get the correct comparison.

• * Tax (New Regime) — after considering standard deduction of Rs.75000.00
• ** Tax (Old Regime) —after considering standard deduction of 50000.00 & with  no other deductions claimed

The Breakeven Framework: When Does the Old Regime Win?

The breakeven point is the level of total deductions at which the old regime becomes equal to or better than the new regime. If your actual deductions exceed this level, the old regime saves more. Below it, the new regime wins.

Key Deductions and Exemptions Under the Old Regime

The old tax regime allows taxpayers to claim certain exemptions and deductions based on their income, investments and eligible expenses. The key provisions relevant to the regime comparison include:

The practical implication: If your total eligible deductions — including 80C, 80D, HRA, home-loan interest, NPS and other applicable deductions — fall below the breakeven threshold for your income level, the new regime may save more tax. If they exceed it, the old regime may be more beneficial. The right choice should therefore be based on your actual eligible deductions and complete income profile.

What You Can — and Cannot — Claim Under Each Regime

This is where most people make their mistakes. They assume the old regime is just about 80C. In reality, the deduction landscape is broader — and some people are significantly underestimating how much they can legitimately claim.

Which Regime Is Right for You: Decision by Profile

Rather than a single universal answer, here is the framework by taxpayer profile. Apply the one that matches your situation.

💼  Salaried — Income up to ₹12.75 lakh

• Zero tax if gross salary is up to ₹12.75 lakh (₹12 lakh taxable after ₹75K standard deduction)
• Section 87A rebate of ₹60,000 eliminates the entire tax liability
• No deductions needed — the regime does the work
• Simple, zero compliance effort, no investment products required

→ Talk to CPC Services

🏠  Salaried — Income ₹15–25 lakh

• Run the breakeven calculation (see table above) with your actual deductions
• If you pay significant rent in a metro city (HRA exemption ₹2–4 lakh) + max 80C + health insurance: old regime likely wins
• If you own your home outright and have modest investments: new regime likely wins
• A home loan with interest above ₹1.5 lakh strongly favours the old regime at this income level
• Do not guess — model both regimes with your actual numbers before declaring to your employer

→ Talk to CPC Services for a Regime Comparison

📈  Salaried — Income Above ₹50 lakh

• Surcharge under new regime is capped at 25%; old regime can go up to 37% above ₹5 crore
• At very high income levels, the surcharge difference alone can outweigh deduction benefits
• Exception: if you have an active home loan with substantial interest, the deduction may still favour old regime
• This decision requires a precise calculation — the numbers at high income levels move significantly
• Consult a professional before defaulting — the surcharge difference can be lakhs

→ Explore Direct Tax Advisory at CPC

💻  Freelancers and Professionals

• No HRA (unless paying rent and claiming under old regime)
• No home loan deduction under new regime (except for let-out property)
• New regime wins if deductions below breakeven for your income level
• Can switch between regimes every year (unlike business income — see below)
• Advance tax planning matters: model the full year before the 15 September Q2 deadline

→ Explore Direct Tax Advisory

🏭  Business Owners and SME Directors

• If you have business income (proprietorship, partnership, LLP, company director with salary + business income), the regime choice is NOT flexible
• Business taxpayers who choose the old regime can switch to new regime — but once they switch to new regime, they can only return to old regime ONCE in their lifetime
• This lock-in makes the decision more consequential: it is not an annual decision, it is a structural one
• The new regime removes all business-related expense deductions (beyond legitimate business expenses under Section 37)
• Most SME owners and directors benefit from a formal review before committing to either regime

→ Talk to CPC Services about Business Tax Planning

The Deadline Most People Miss: When to Declare Your Regime Choice

Choosing the right regime is only half the decision. Communicating it at the right time is the other half — and missing this has real financial consequences.

For Salaried Employees

Your employer asks for a regime declaration at the start of the financial year — typically April or at the time of joining — to determine TDS deduction from salary. If you do not declare, your employer defaults to the new regime.

• The consequence of not declaring: If you are better off under the old regime but did not declare it to your employer, TDS is deducted at new regime rates throughout the year. You can correct this when filing your ITR — but you will have paid excess TDS all year and will only get the refund after ITR processing, which can take months.
• What to do now: If you have not declared your regime choice for FY 2026-27 yet, contact your HR or payroll department. Many employers accept a revised declaration during the year, particularly before October. After October, most payroll systems lock the declaration for the year.

For Business Owners and Freelancers

Your regime choice is declared when filing the ITR, not in advance. However, if you have business income and want to claim the old regime, you must file Form 10-IE (for opting out of the new regime) before or at the time of ITR filing.

• The advance tax angle: The 15 September 2026 deadline is the second instalment of advance tax (45% of estimated annual tax). If you do not know your regime for the year, you cannot accurately estimate your advance tax — which means either overpaying (and waiting for a refund) or underpaying (and paying 1% per month interest under Section 234B/234C). This is why August regime planning has a direct cash flow consequence.

Two Real-World Comparisons

Two profiles — same income, different circumstances — to show how the decision plays out in practice.

Profile 1: Anil, 34, Software Professional, Delhi — ₹18 lakh gross salary

Profile 2: Priya, 29, Marketing Manager, Faridabad — ₹18 lakh gross salary (owns home)

Same salary. Same city (both NCR). Anil rents and claims a sizeable HRA exemption, which narrows the gap — the old regime still saves him ₹70,720. Priya owns her home with only a small loan balance, so she has far less to claim under the old regime — and for her, the new regime wins decisively, by ₹1,30,000. The decision is not about income level alone. It is about your specific deduction profile: the more you can genuinely claim under the old regime, the smaller the new regime’s advantage becomes — but at this income level, the new regime’s lower rates and higher standard deduction give it a real head start that only a substantial deduction profile can overcome.

Related Reading

• → ITR Filing 2026: Step-by-Step Guide + Common Mistakes to Avoid
• → July 2026 GST & TDS Due Dates: Don’t Miss These Compliance Deadlines
• → 10 Signs Your Growing Business Needs a Virtual CFO Right Now

The post New vs Old Tax Regime FY 2026-27: The Right Choice for You first appeared on CPC Services Pvt. Ltd..