Tax Computation and Advance Tax

Overview

Income tax is meant to be paid as you earn, not in one lump at filing time. Advance tax is that pay-as-you-earn system: you estimate your total income for the year, work out the tax after TDS and TCS, and pay it in instalments on fixed dates. This service covers the estimate, the instalment plan, the challans and the year-end true-up against what you actually earned.

Who needs it

• Salaried people with income that has no TDS, such as freelance fees, rent, interest, or capital gains.
• Professionals and small businesses, including those on presumptive taxation.
• Investors who sold shares, mutual fund units, property or crypto assets during the year.
• Anyone who received a notice or interest demand for short payment in an earlier year.
• Companies, firms and LLPs, which pay advance tax on the same schedule.

What Zenith does

Zenith listens first: which incomes you expect, what TDS is already deducted, and whether you follow the old or the new regime. A relationship manager is assigned and an assignment-specific checklist is shared. Then an authorised professional:

• Estimates your total income and deductions for the year, and computes tax with surcharge and cess.
• Compares the old and new regime for your numbers, so the estimate uses the better one.
• Subtracts TDS and TCS (from Form 26AS and the AIS) to find the net liability.
• Prepares an instalment schedule with the exact amount for each due date.
• Guides the payment on the e-filing portal, or pays it with your approval, and keeps the challan details (BSR code, serial number, date) for the return.
• Revises the estimate mid-year when income changes, for example after a large capital gain.

Zenith does not move your money without your instruction, and your portal password is never needed.

Eligibility and key rules

• Advance tax is due when the estimated tax for the year, after TDS and TCS, is more than Rs 10,000.
• Resident senior citizens (60 and above) with no business or professional income are exempt.
• Presumptive taxpayers under sections 44AD and 44ADA may pay the whole advance tax in one instalment by 15 March. This is not available under section 44AE.
• Income that cannot be predicted, such as capital gains or lottery winnings, is paid in the instalments still remaining after it arises, or by 31 March if none remain.
• Interest rules are sections 234B and 234C of the Income-tax Act, 1961. The public guides read for this service list the equivalents as sections 424 and 425 of the Income-tax Act, 2025 for FY 2026-27 onward. Zenith applies the Act that governs your tax year.

Documents required

• PAN and the last filed return (or computation).
• Form 26AS and the Annual Information Statement for the year.
• Salary slips or Form 16 so far, and details of any other employer.
• Details of business or professional income so far: profit and loss to date, turnover, or a projection.
• Capital gains statements from brokers, mutual fund registrars or property sale documents.
• Interest certificates and rent receipts.
• Investment and deduction proofs if you follow the old regime.
• Challans of advance tax already paid.

Process and timeline

1. Share your income picture and documents through the request form.
2. The professional prepares an estimate and recommends the regime.
3. You review the instalment schedule and approve it.
4. Payment is made on the e-filing portal under Income Tax, minor head Advance Tax (100), for the correct tax year.
5. You receive the challan copy. The estimate is refreshed before each later due date if income has changed.
6. At filing time the paid challans are carried into the return and any balance is paid as self-assessment tax (minor head 300).

Timelines depend on how complete your records are and on the dates in the table below.

Government fees, penalties and due dates

Instalment	Due date	Cumulative tax to be paid
1st	15 June	15%
2nd	15 September	45%
3rd	15 December	75%
4th	15 March	100%

• Interest for an instalment shortfall is 1% per month. It runs for 3 months for the first three instalments and 1 month for the last.
• No instalment interest is charged if at least 12% is paid by 15 June and at least 36% by 15 September, and the full amount is paid by 15 March.
• Interest for default in advance tax overall (section 234B) is 1% per month when less than 90% of the tax is paid by 31 March.
• There is no government fee for paying tax. Bank charges, if any, are shown separately.

Amounts and dates above reflect public sources read in October 2026 and change with notifications, so Zenith confirms the current figures in your quotation.

Common mistakes

• Paying only on the basis of salary TDS and ignoring freelance, rental, interest or capital gains income.
• Paying under the wrong tax year or minor head. Challan correction is possible, but only within a short window (assessment year within 7 days, major or minor head within 30 days).
• Forgetting to carry the BSR code and challan serial number into the return.
• Assuming a senior citizen is always exempt, when business income exists.
• Treating one big payment in March as equal to timely instalments. Interest for the earlier shortfall still applies.
• Not revising the estimate after a large sale or bonus.

FAQs