Section 140A is about one simple idea: pay your dues before you file your return. Think of it like a hotel checkout — you settle the bill first, then you leave. The amount you pay at this stage is called self-assessment tax.
Here is how you calculate it. Take your total tax on income as per your return. From that, subtract everything you have already paid during the year — advance tax, TDS/TCS deducted, foreign tax relief claimed under sections 90/91/90A, and MAT/AMT credit set off under sections 115JAA or 115JD. Whatever is left is your self-assessment tax. But you do not stop there. Section 140A says you must also pay, before filing: interest u/s 234A (for filing your return late), interest u/s 234B (for paying advance tax short of 90% of assessed tax), and fee u/s 234F (₹1,000 if income ≤ ₹5 lakhs; ₹5,000 if income > ₹5 lakhs, when you file after the due date). Your return must be accompanied by proof of payment — typically the Challan 280 BSR code receipt.
Now here is the part that is almost always tested: the priority order when you cannot pay the full amount. The Explanation to Section 140A(1) lays it out clearly — short payments are adjusted in this sequence: Fee first → Interest next → Tax last. So if Mr. Sharma owes ₹5,000 fee + ₹2,000 interest + ₹20,000 tax and pays only ₹15,000, the entire fee is absorbed first, then interest, and only ₹8,000 goes toward tax. The remaining ₹12,000 tax stays outstanding. For interest computation: 234A interest is calculated on the tax as per return minus advance tax, TDS, foreign credits, and MAT credit. 234B interest is on assessed tax (tax on declared income minus TDS, foreign credits, MAT credit) minus advance tax paid. This section is regularly tested as a 4–5 mark computation or a short theory question on the priority of adjustment.
Example 1 — Calculating self-assessment tax with 234B interest
Ms. Kavitha files her ITR for AY 2025-26 on 31st July 2025 (the due date). Her details:
- Tax on total income: ₹2,40,000
- TDS deducted by employer: ₹1,20,000
- Advance tax paid: ₹80,000
- No foreign income, no MAT credit
Step 1 — Balance tax after credits:
₹2,40,000 − ₹1,20,000 (TDS) − ₹80,000 (advance tax) = ₹40,000
Step 2 — Check 234B liability:
Assessed tax = ₹2,40,000 − ₹1,20,000 = ₹1,20,000
90% of assessed tax = ₹1,08,000
Advance tax paid = ₹80,000 (short by ₹40,000, so 234B applies)
234B interest = ₹40,000 × 1% × 4 months (April to July) = ₹1,600
Step 3 — No 234A or 234F (filed on due date)
Self-assessment tax to pay before filing = ₹40,000 + ₹1,600 = ₹41,600
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Example 2 — Short payment and priority of adjustment
Mr. Arjun's self-assessment calculation shows: Tax payable = ₹20,000 | 234B interest = ₹2,000 | 234F fee = ₹5,000. Total dues = ₹27,000. He can only arrange ₹15,000 right now.
Step 1 — Fee adjusted first: ₹5,000 fee fully absorbed. Balance: ₹15,000 − ₹5,000 = ₹10,000
Step 2 — Interest adjusted next: ₹2,000 interest fully adjusted. Balance: ₹10,000 − ₹2,000 = ₹8,000
Step 3 — Tax adjusted last: ₹8,000 adjusted against ₹20,000 tax. Tax still outstanding = ₹12,000
Arjun must pay ₹15,000 now and file his return. The remaining ₹12,000 tax will be demanded during regular assessment proceedings.
📖 Bare Act text — Section 140A, Income Tax Act 1961
(click to expand)
(1) Where any tax is payable on the basis of any return required to be furnished under section 115WD or section 115WH or section 139 or section 142 or section 148 or section 153A or, as the case may be, section 158BC, after taking into account,— (i) the amount of tax, if any, already paid under any provision of this Act; (ii) any tax deducted or collected at source; (iii) any relief of tax or deduction of tax claimed under section 90 or section 91 on account of tax paid in a country outside India; (iv) any relief of tax claimed under section 90A on account of tax paid in any specified territory outside India referred to in that section; and (v) any tax credit claimed to be set off in accordance with the provisions of section 115JAA or section 115JD, the assessee shall be liable to pay such tax, together with interest and fee payable under any provision of this Act for any delay in furnishing the return or any default or delay in payment of advance tax, before furnishing the return and the return shall be accompanied by proof of payment of such tax interest and fee. Explanation.—Where the amount paid by the assessee under this sub-section falls short of the aggregate of the tax interest and fee as aforesaid, the amount so paid shall first be adjusted towards the fee payable and thereafter towards the interest payable as aforesaid and the balance, if any, shall be adjusted towards the tax payable. (1A) For the purposes of sub-section (1), interest payable,— (i) under section 234A shall be computed on the amount of the tax on the total income as declared in the return as reduced by the amount of,— (a) advance tax, if any, paid; (b) any tax deducted or collected at source; (c) any relief of tax or deduction of tax claimed under section 90 or section 91 on account of tax paid in a country outside India; (d) any relief of tax claimed under section 90A on account of tax paid in any specified territory outside India referred to in that section; and (e) any tax credit claimed to be set off in accordance with the provisions of section 115JAA or section 115JD; (ii) under section 115WK shall be computed on the amount of tax on the value of the fringe benefits as declared in the return as reduced by the advance tax, paid, if any. (1B) For the purposes of sub-section (1), interest payable under section 234B shall be computed on an amount equal to the assessed tax or, as the case may be, on the amount by which the advance tax paid falls short of the assessed tax. Explanation.—For the purposes of this sub-section, "assessed tax" means the tax on the total income as declared in the return as reduced by the amount of,— (i) tax deducted or collected at source, in accordance with the provisions of Chapter XVII, on any income which is subject to such deduction or collection and which is taken into account in computing such total income; (ii) any relief of tax or deduction of tax claimed under section 90 or section 91 on account of tax paid in a country outside India; (iii) any relief of tax claimed under section 90A on account of tax paid in any specified territory outside India referred to in that section; and (iv) any tax credit claimed to be set off in accordance with the provisions of section 115JAA or section 115JD.