Income Tax Filing for Businesses in India: Forms & Process (2026)

Income tax filing for businesses in India depends on the entity type (proprietorship, partnership, LLP, or company), whether presumptive taxation applies, and whether a statutory tax audit is required based on turnover. Proprietorships and partnerships use ITR-3 or ITR-4 (presumptive scheme), while companies must file ITR-6, and every business — audited or not — must correctly determine its due date, since audit cases get until 31 October rather than the standard 31 July.

Choosing the Right ITR Form

Entity Type	Applicable Form
Proprietorship/individual with business income (not opting presumptive)	ITR-3
Proprietorship/professional opting for presumptive taxation	ITR-4 (Sugam)
Partnership firm / LLP	ITR-5
Company (private limited, OPC, public)	ITR-6

Presumptive Taxation: A Simpler Option for Eligible Businesses

Small businesses with turnover up to the specified threshold can opt for presumptive taxation under Section 44AD, declaring a fixed percentage of turnover as taxable profit (with a lower rate for digital/banking-channel receipts) without maintaining detailed books of account or undergoing an audit. Professionals such as consultants, doctors, and freelancers with gross receipts up to the specified threshold can similarly opt under Section 44ADA, declaring 50% of gross receipts as taxable income. Opting in significantly simplifies compliance but comes with restrictions on switching out of the scheme frequently.

When Tax Audit Becomes Mandatory

A statutory tax audit under Section 44AB becomes mandatory once business turnover crosses the specified threshold (a higher threshold applies where cash transactions are limited to a small percentage of total transactions), or once professional gross receipts cross the specified threshold for professionals. Audit also becomes mandatory if a business declares presumptive income below the prescribed rate under Section 44AD while its total income exceeds the basic exemption limit. Audited businesses must get the audit report filed by 30 September and the ITR itself by 31 October.

Step-by-Step Business ITR Filing Process

1. Step 1: Finalise books of account (or determine presumptive income, if opted) and reconcile with GST returns and TDS records.
2. Step 2: Determine if a tax audit is required based on turnover, cash transaction proportion, and presumptive income declared.
3. Step 3: Complete the audit (if applicable) and file Form 3CA/3CB and 3CD by 30 September.
4. Step 4: Compute total taxable income, claim eligible deductions, and pay balance self-assessment tax.
5. Step 5: File the correct ITR form by the applicable due date and e-verify within 30 days.

Common Mistakes to Avoid

• Filing under presumptive taxation without checking eligibility limits and switching restrictions
• Missing the 30 September audit report deadline while assuming only the 31 October ITR deadline matters
• Not reconciling business turnover between GST returns and income tax records, triggering mismatch notices
• Choosing ITR-4 when actual circumstances require ITR-3 (for example, having capital gains or foreign assets, which aren’t covered under ITR-4)
• Underestimating advance tax instalments through the year, leading to interest under Sections 234B/234C

Carry Forward and Set-Off of Business Losses

A business loss can generally be set off against income from other heads in the same year (barring some restrictions) and, if not fully absorbed, carried forward for up to eight assessment years to offset future business profits, provided the return is filed by the original due date. Unabsorbed depreciation, by contrast, can be carried forward indefinitely with no time limit. This carry-forward benefit is one of the strongest reasons to file on time even for a business showing a loss in a given year — many founders skip filing when there’s no tax payable, unknowingly forfeiting a valuable future tax shield.

This matters most for early-stage businesses that typically run losses in their first few years before turning profitable — a founder who skips filing during the loss-making years because “there’s nothing to pay” often discovers, once the business finally turns a profit, that those earlier losses can no longer be carried forward to reduce the new tax bill, simply because the original returns were filed late or not at all.

How ComplianceKaro Helps

We determine the correct ITR form and taxation scheme for your business, manage audit coordination where required, and reconcile GST and TDS data before filing. See our ITR filing campaign and accounting and bookkeeping service. Book a free consultation for your business tax filing.

FAQ

Which ITR form should a small proprietorship business use?

Most eligible small proprietorships use ITR-4 (Sugam) under presumptive taxation for simplicity, or ITR-3 if they maintain regular books of account or don’t meet presumptive scheme eligibility.

Is tax audit mandatory for every business?

No, tax audit is mandatory only once turnover or gross receipts cross specified thresholds, or in certain cases where presumptive income is declared below the prescribed rate. Businesses below these thresholds are exempt.

What is the due date for businesses requiring a tax audit?

The tax audit report is due by 30 September, and the ITR itself is due by 31 October for businesses requiring an audit for the relevant assessment year.

File your business ITR correctly. Book a free consultation or start with our ITR filing campaign.