The due date to file an income tax return (ITR) for students, pensioners, salaried individuals, and others who are not liable for a tax audit is July 31, 2026, for AY 2026-27. However, for individuals with business income or those requiring a tax audit, the due date for filing ITR is August 31.There are about three ITR forms (ITR-1, ITR-2, and ITR-3) which most students, salaried employees, and pensioners need to file depending on their source of income.Who is eligible to file ITR-3?ITR-3 is to be used by an individual or a Hindu Undivided Family (HUF) who is having income under the head 'profits or gains of business or profession' and who is not eligible to file Form ITR?1 (Sahaj), ITR?2, or ITR?4 (Sugam). Chartered Accountant Abhishek Soni, Co-Founder of Tax2Win, says that ITR-3 also applies when business income exists alongside other sources of income. Thus, apart from business income, taxpayers filing ITR-3 can also report income from:Salary or pensionHouse propertyCapital gainsOther sources of incomeForeign assets and foreign incomeSince it captures multiple income sources and detailed financial information, ITR-3 is considered one of the most comprehensive income tax return forms.Who cannot file ITR-3?Soni says that that the following taxpayers are not eligible to file ITR-3:CompaniesLLPsPartnership firmsTrustsIndividuals eligible to file ITR-1Individuals eligible to file ITR-2Taxpayers opting for presumptive taxation under ITR-4Also read: ITR filing: Received Section 143(1) intimation with tax demand? Respond within 30 days or risk being treated as an ‘assessee in default’; know how to do itHow to file ITR-3 online through e-filing ITR portalAccording to the income tax department's website, ITR-3 has the following sections that you need to fill up (applicable schedule) before submitting the form:Part A- GeneralPart B-TIPart B- TTISchedule-ITSchedule TDSSchedule TCSManufacturing accountTrading AccountP&LBalance sheetSchedule OISchedule QDSchedule SSchedule HPSchedule BPSchedule DPMSchedule DOASchedule DEPSchedule CGSchedule OSSchedule CYLASchedule BFLASchedule CFLSchedule VI-A80GSchedule SPISchedule SISchedule EISchedule PTISchedule FSISchedule TRSchedule 5ASchedule FASchedule ALAlso read: How to select the right ITR form based on your income for AY 2026-2027Step-by-step guide:Step 1: In the Part A General section of the ITR, you need to verify the pre-filled data from your e-Filing profile. You will not be able to edit some of your personal data directly in the form. However, you can make the necessary changes by going to your e-Filing profile. You can edit your contact details, filing status, residential status, and bank details in the form itself.