Self Assessment Tax

Self-assessment tax is the balance income tax a taxpayer computes and pays on their own before filing an income tax return. For Tax Year 2026-27 (income earned 1 April 2026 to 31 March 2027) it is governed by Section 266 of the Income-tax Act, 2025, which replaced Section 140A of the Income-tax Act, 1961 (still relevant for FY 2025-26 returns filed in AY 2026-27). It is the amount left after tax deducted at source (TDS), tax collected at source (TCS), advance tax paid, and eligible reliefs and MAT/AMT credit are set off against the total tax due, plus any interest and fee. A return cannot be validly furnished until this liability is cleared.

How it is calculated

Total tax on the returned income, plus applicable interest and late-filing fee, minus TDS/TCS, advance tax and eligible reliefs and credits. Any shortfall is the self-assessment tax, paid before submitting the ITR. The new Act uses a single "Tax Year" and drops the separate assessment year, so income of FY 2026-27 is simply Tax Year 2026-27.

Interest that gets added

• Section 423 (old 234A) - 1% per month for filing the return after the due date.
• Section 424 (old 234B) - 1% per month where advance tax paid is under 90% of the assessed tax.
• Section 425 (old 234C) - 1% per month for shortfall or deferment in advance-tax instalments.

How to pay

Pay through the e-Pay Tax facility at incometax.gov.in, which generates Challan ITNS 280N. Select "Self-Assessment Tax (300)" and Tax Year 2026-27, then pay by net banking, debit card, UPI or at an authorised bank counter. Record the BSR code, challan serial number and date (the CIN) in the return so credit reflects in Form 26AS and the AIS. The CBDT administers the levy.