Advance tax and self-assessment tax are both ways of paying income tax directly, but they apply at different stages. Advance tax is paid during the year in which income is being earned, based on an estimate of the year's tax liability. Self-assessment tax is the balance paid after the year has ended, when the return is being finalised and the taxpayer finds that TDS, TCS and advance tax do not fully cover the final liability.
The Income Tax Department's ITR-1 FAQ explains the basic distinction and the advance-tax instalment framework. Its current Tax Payments FAQ also confirms that the obligation to discharge tax through TDS/TCS, advance tax and self-assessment tax continues under the Income Tax Act, 2025.
When does advance tax become relevant?
For individuals, the Department's ITR-1 FAQ states that advance tax becomes relevant where estimated tax for the year exceeds ₹10,000. Salary TDS may already cover much of a salaried person's liability, but additional income such as interest, rent or capital gains can create a shortfall. Business and professional income can create the same issue because tax may not be fully collected at source.
The practical calculation is not simply tax on gross receipts. Estimate total taxable income for the year, compute the applicable tax, surcharge and cess, then reduce expected TDS/TCS and other eligible credits. The resulting estimated net liability determines how much advance tax needs to be funded.
What are the normal advance-tax instalments?
The Department's ITR-1 guidance sets out the familiar cumulative instalment pattern for individuals: 15% of the estimated liability by 15 June, 45% by 15 September, 75% by 15 December and 100% by 15 March. Each later percentage is cumulative, so tax already paid is reduced when determining the next instalment.
What is self-assessment tax?
Self-assessment tax is the final balancing payment made when the return computation shows tax still payable after giving credit for taxes already paid or collected. The Department's ITR-1 FAQ describes the return-preparation flow: after TDS and advance-tax details are entered, the system computes whether an amount remains payable; that amount must be paid and the challan details reflected in the return before submission.
Self-assessment tax is therefore not a substitute for advance tax planning. A taxpayer can pay the final balance later, but underpayment or deferment of advance tax can still produce statutory interest where the relevant conditions are met.
Advance tax vs self-assessment tax: a worked example
Assume a consultant estimates during the year that total tax after TDS will be ₹2,00,000. The consultant should plan advance-tax payments under the applicable instalment rules rather than wait for return filing. After year-end, final accounts show that the actual net tax liability is ₹2,18,000. If ₹2,00,000 has already been discharged as advance tax, the remaining ₹18,000, together with any applicable interest or other amount in the return computation, is paid as self-assessment tax before the return is filed.
If the consultant had paid only ₹80,000 during the year and waited to clear the rest as self-assessment tax, the final tax may still be paid, but the advance-tax default can have interest consequences. This is why cash-flow timing and tax-compliance timing should be monitored together.
Why sections 234B and 234C matter
For FY 2025-26 and AY 2026-27, the Department's Tax Payments FAQ confirms that defaults in advance-tax payment remain governed by the Income-tax Act, 1961, including sections 234B and 234C. Section 234B deals with default in payment of advance tax, while section 234C deals with deferment of advance-tax instalments. The Department's transition FAQ also states that the corresponding framework continues under the 2025 Act.
The practical lesson is that paying a large amount as self-assessment tax before filing the return does not retrospectively turn it into timely advance tax. Interest should be computed through the applicable return utility or tax computation based on the facts of the year.
How to pay through the e-Filing portal
The Department's challan creation manual explains the e-Pay Tax workflow. Taxpayers can generate challans through the portal by selecting the applicable Income Tax Act, tax type and tax period. For AY 2026-27 and earlier years, payments remain under the Income-tax Act, 1961 framework; for Tax Year 2026-27 onwards, the portal uses the Income Tax Act, 2025 framework and the new challan naming.
This transition makes the year selection especially important. The Department specifically warns taxpayers to choose AY 2026-27 for payments relating to FY 2025-26 and Tax Year 2026-27 for payments relating to FY 2026-27 so that credit is posted to the correct period.
Practical payment checklist
- Estimate full-year income: include salary, business or professional income, interest, rent, capital gains and other taxable sources as applicable.
- Estimate credits: reduce expected TDS/TCS and taxes already paid from the projected liability.
- Review before every instalment: update the estimate when income, deductions or capital gains change materially.
- Use the correct payment type: select advance tax for payments made during the relevant year and self-assessment tax for the final post-year-end balance.
- Select the correct Act and period: this is particularly important during the 2026 transition between AY-based and Tax-Year-based portal workflows.
- Save challan evidence: retain the CRN/CIN and confirm that the payment appears in the relevant tax records before filing.
- Recompute interest: do not assume that payment of the final balance eliminates advance-tax interest.
Common mistakes to avoid
- Waiting until ITR filing even when a material advance-tax liability is foreseeable.
- Using gross income instead of estimated taxable income and available tax credits.
- Treating the 15%, 45%, 75% and 100% instalments as separate percentages rather than cumulative targets.
- Assuming self-assessment tax automatically cures an earlier advance-tax default without interest.
- Selecting the wrong assessment year, tax year, Act or payment type on the e-Pay Tax portal.
- Failing to revise the estimate after a large capital gain, bonus, interest receipt or business-profit change.
Practical takeaway
Advance tax is a during-the-year funding obligation; self-assessment tax is the final balancing payment before return filing. The strongest process is to forecast tax through the year, update the estimate before each applicable instalment, preserve payment evidence and use self-assessment tax only for the genuine final shortfall. During the 2026 transition, also verify the correct Act and tax period on the portal before making payment.
