ITR-3 for AY 2026-27: Who Must File, Deadlines & AIS Guide

The income tax return filing season for Assessment Year 2026-27 (Financial Year 2025-26) is officially open. The Income Tax Department activated the ITR-3 online utility in June 2026, and with the deadline clock running, practitioners and business owners who fall under this form category need to move now. If your CA firm handles proprietors, professionals, or partners — and most practices do — this is the filing you cannot afford to rush.

This year carries additional weight. The Income Tax Act, 2025 — which replaced the Income Tax Act of 1961 with effect from April 1, 2026 — restructured how income schedules are laid out, how deductions are cross-referenced, and what disclosures the portal automatically pulls from your Annual Information Statement (AIS). CAs who filed ITR-3 routinely last year will notice both structural and operational differences in the new form.

Who Must File ITR-3?

ITR-3 applies to individuals and Hindu Undivided Families (HUFs) earning income from a proprietary business or profession, or those receiving income from a partnership firm in addition to other income heads. File ITR-3 if you:

• Own and operate a sole-proprietorship business (trading, manufacturing, or services)
• Earn professional income as a doctor, consultant, architect, advocate, or any other notified professional
• Are a partner in a partnership firm or LLP and receive salary, bonus, commission, or interest on capital from the firm
• Have capital gains — equity shares, mutual funds, or immovable property — alongside business or professional income
• Have brought-forward losses from prior assessment years under any head of income
• Own more than two house properties generating rental income

When ITR-4 Applies Instead

If your business income falls entirely under presumptive taxation — Section 44AD for businesses with turnover up to ₹3 crore at the 6% or 8% rate, or Section 44ADA for professionals with gross receipts up to ₹75 lakh at 50% — and you have no capital gains, no carry-forward losses, and rental income from at most two properties, file ITR-4 (Sugam). Switch to ITR-3 the moment any of those parameters change.

Partner Income: The Most Overlooked Piece

Every partner must file their own ITR-3 even though the partnership firm submits a separate return (ITR-5). Your ITR-3 must capture:

• Share of profit from the firm — exempt under old Section 10(2A) of the Income Tax Act, 1961 (corresponding provision under the Income Tax Act, 2025) — disclose under Schedule EI; do not omit this entry
• Remuneration received from the firm — salary, bonus, commission — taxable as business income in your hands under Schedule BP
• Interest on capital credited by the firm — taxable to the extent the firm deducted it as an allowable expense, typically up to 12% per annum as per the partnership deed

A partner who received ₹18 lakh as profit share and ₹6 lakh as firm remuneration must show ₹6 lakh as gross receipts under Schedule BP and ₹18 lakh as exempt income under Schedule EI. The firm's tax audit report (Form 3CB and Form 3CD) is the authoritative source for these figures.

Filing Deadlines for AY 2026-27

The July 31 deadline is firm for non-audit cases. Missing it means interest on unpaid tax at 1% per month under Section 234A plus a late-filing fee of ₹5,000 (₹1,000 if total income is below ₹5 lakh) under Section 234F. Do not count on an extension — file clean by July 31.

What Changed Under the Income Tax Act, 2025

The new Act does not alter tax slabs or most deduction ceilings, but it reorganises the statute significantly. Three changes matter most for ITR-3 filers this season:

Consolidated Deductions Chapter

All income-linked deductions — the old Chapter VI-A provisions from 80C to 80U — are now in a single Deductions Chapter with revised section numbering. The ₹1.5 lakh investment limit under old Section 80C remains unchanged, as do the ceilings for health insurance (old Section 80D: ₹25,000 for self and family, ₹50,000 for senior citizens), NPS contributions (old Section 80CCD), and home loan interest (old Section 24(b): ₹2 lakh for self-occupied property). Your tax software's section-number mapping needs updating before the filing utility references these provisions correctly.

Revised Business Income Disclosures in Schedule BP

The updated ITR-3 requires separate disclosure of digital payment receipts versus cash receipts within Schedule BP for businesses with gross receipts above ₹10 lakh. This breakdown determines whether the higher ₹10 crore audit threshold (applicable when 95% of transactions are digital) or the standard ₹1 crore threshold applies. If your books do not already tag receipts by mode of payment, complete this reconciliation before opening the portal.

Old Tax Regime Must Be Actively Elected

The new Act makes the new tax regime (lower slabs, minimal deductions) the default. To claim deductions — old Section 80C investments, 80D health insurance, HRA, LTA — your client must file Form 10-IEA on or before the return due date. For non-audit proprietors and professionals, that date is July 31, 2026. Missing the Form 10-IEA election means losing all Chapter VI-A deductions for the full financial year with no retrospective remedy available.

Documents to Gather Before Opening the Portal

Filing without a complete document set causes errors that generate notices months later. Collect all of these before your client logs in:

From business or firm records:

• Profit and loss account and balance sheet for FY 2025-26 (finalised and signed)
• Partnership deed or LLP agreement specifying remuneration and interest clauses, if the client is a partner
• Tax audit report (Form 3CA/3CB and Form 3CD) for businesses or professionals above the audit threshold
• Depreciation schedule for all fixed assets under the proprietorship

From the Income Tax Portal (incometax.gov.in):

• Annual Information Statement: log in → Services → AIS → Download
• Form 26AS: available in the same section
• Form 16A or TDS certificates from payers who deducted tax on professional fees or contract receipts

Supporting documents:

• Capital gains statement from the stockbroker covering all equity, F&O, and debt instrument transactions
• Consolidated Account Statement from NSDL or CDSL listing all mutual fund transactions in FY 2025-26
• Bank statements for every account held during the year — savings, current, OD, FD, and RD
• Loan interest certificates for any home loan, loan against property, or business loan outstanding during the year

Reconciling AIS and Form 26AS Before You File

This is the most important pre-filing step for AY 2026-27 — and the step most frequently skipped under deadline pressure. The Income Tax Department now routinely issues automated adjustments under Section 143(1)(a) based solely on AIS data, without any formal scrutiny assessment. A return filed without AIS reconciliation invites these adjustments within weeks of submission.

What AIS Contains That Form 26AS Does Not

Form 26AS was always limited to TDS credits, advance tax challans, and self-assessment tax payments. The AIS captures far more:

GST turnover cross-check: For every GST-registered taxpayer, the department pulls aggregate supplies from GSTR-1 filings into the AIS and maps them against the ITR's declared gross receipts. If your GSTIN's aggregate taxable supply for FY 2025-26 was ₹92 lakh but Schedule BP in the ITR-3 shows gross receipts of ₹78 lakh, the gap triggers an automated query. Common legitimate reasons — advances received and adjusted, credit notes issued, exempt supplies, or export supplies — must be documented in pre-filing reconciliation workings rather than explained later in a notice reply.

FD interest even without TDS deduction: Banks report FD interest credited to depositors to the AIS system, not just amounts on which TDS was deducted. If your client submitted Form 15G or 15H to prevent TDS on a ₹95,000 fixed deposit interest receipt, that amount still appears in the AIS under 'interest from deposits.' Leaving it out of Schedule OS (Other Sources) in the return creates a reportable gap.

Securities transactions via depositories: Purchase and sale of equity shares, mutual fund units, bonds, and debentures — as reported by NSDL, CDSL, and registrar and transfer agents — populate the AIS with transaction-level data including dates and values. A client who ran 24 SIP installments and redeemed units in FY 2025-26 will have multiple line items in the AIS. A Schedule CG that presents a single summarised gain figure without individual FIFO allocation by installment will not reconcile with AIS data.

Reconciliation Workflow

1. 1Download the AIS in PDF or JSON format from the Income Tax Portal for each client before opening the ITR utility
2. 2Map every AIS entry to the corresponding line in the client's profit and loss account, bank statement, or capital gains workings
3. 3For disputed AIS entries — errors, duplicates, or transactions belonging to another PAN — submit feedback through the AIS module on the portal; corrections can be submitted up to the date of filing
4. 4Allow 48–72 hours for AIS feedback to update the portal display, then download the revised AIS before finalising the return numbers
5. 5Where a legitimate gap exists — FD interest earned but not booked, advance payments included in GST returns but not yet recognised as income — correct the books before finalising the ITR, not the reverse

If a return has already been filed and a mismatch surfaces after submission, file a revised return before March 31, 2027 rather than waiting to respond to a notice.

Common Mistakes That Generate Notices

Omitting Schedule EI for profit share: Partners whose share of firm profit is exempt from tax must still complete Schedule EI in their ITR-3. Leaving it blank causes the automated processing system to treat the unaccounted amount as undisclosed income, generating a deficiency notice.

Treating partner remuneration as employment salary: Partner remuneration — even when called "salary" in the partnership deed — is business income taxable under Schedule BP, not Schedule S. Filing it under Schedule S incorrectly applies the ₹75,000 standard deduction, understating taxable income and triggering a processing adjustment.

Missing Form 10-IEA for old regime election: Proprietors and professionals who want to claim 80C, 80D, or HRA deductions must submit Form 10-IEA before the ITR due date. The portal allows filing the return in old-regime mode without this form — but the deductions are subsequently disallowed if the election form is absent from the system.

Accrual versus receipt confusion on FD interest: FD interest is taxable on an accrual basis regardless of whether the deposit has matured or TDS was deducted. Interest accrued during FY 2025-26 on a two-year FD maturing in FY 2026-27 must be included in the AY 2026-27 return. This is both a common error and a guaranteed AIS mismatch.

Averaged cost basis for SIP redemptions: Mutual fund SIPs require FIFO-based capital gains computation — each installment is a separate acquisition with its own date and NAV. Averaging the cost across all installments understates gains on older, lower-cost units. Use the fund house's capital gains statement or the CAMS or NSDL Consolidated Account Statement for the accurate installment-by-installment breakdown.

Key Takeaways

• ITR-3 is mandatory for sole proprietors, professionals, and partners — the partner's tax-exempt profit share must appear in Schedule EI even though no tax is payable on it
• July 31, 2026 is the deadline for non-audit ITR-3 filers; October 31, 2026 applies to tax audit cases — late filing attracts Section 234A interest and a ₹5,000 Section 234F fee
• The Income Tax Act, 2025 restructured deduction chapters and section numbering — ensure your tax software's references are updated before generating any return this season
• Reconcile every client's AIS against their GST turnover, bank interest records, and securities transactions before filing — automated Section 143(1)(a) adjustments arrive within weeks of a mismatched return
• Elect the old tax regime via Form 10-IEA by July 31 for any client claiming 80C, 80D, HRA, or other Chapter VI-A deductions — there is no remedy after the deadline passes

How corpus Helps

corpus reduces ITR-3 preparation time significantly for CA firms managing multiple proprietor and partnership clients. The platform maintains GST-reconciled books throughout the year, so the turnover figure in your corpus profit and loss account already matches the GSTR-1 aggregate supply — the exact number the Income Tax Department compares against your client's Schedule BP under the AIS cross-check. For partnership clients, corpus records remuneration and interest on capital under the correct income heads at the time of entry, eliminating reclassification work at filing time. The multi-client dashboard gives you a single view of which clients have shared their AIS data, which outstanding TDS credits need to be verified against Form 26AS, and which audit reports are still pending.

Open corpus, export the FY 2025-26 financials for each ITR-3 client, cross-check the AIS, and file before July 31 without the last-minute scramble.