Old vs New Tax Regime for FY 2025-26: A Decision Framework, Not a Verdict

The question arrives every year in the same form: which regime is better? It is the wrong question, because it assumes a general answer exists. The two regimes are not better or worse than one another. They are two different arithmetic structures, and which produces a lower liability depends almost entirely on one variable — how much you are actually able to deduct.

What follows is the method the firm applies. It takes about ten minutes with a salary certificate and a list of investments, and it produces an answer specific to you rather than a rule of thumb borrowed from a colleague whose circumstances are not yours.

1. The position for FY 2025-26

Financial year 2025-26 (assessment year 2026-27) is governed by the Income-tax Act, 1961, as amended by the Finance Act, 2025. The new regime under Section 115BAC is the default. Electing the old regime is a positive act; doing nothing places you in the new regime.

The rate structure under the new regime for a resident individual for this year:

Three features of the new regime matter more than the slabs themselves. The rebate under Section 87A extinguishes the liability of a resident individual whose total income does not exceed ₹12,00,000. A salaried person or pensioner additionally takes a standard deduction of ₹75,000, which lifts the effective threshold accordingly. And the highest surcharge rate is capped at 25%, against 37% in the old regime — which is why the new regime is usually decisive at the very top of the income scale, whatever the deductions.

2. What each regime allows you to deduct

The old regime permits the familiar deductions: Section 80C, the health insurance deduction under 80D, house rent allowance, leave travel concession, the additional National Pension System deduction under 80CCD(1B), donations under 80G, and interest on a housing loan for a self-occupied property under Section 24(b), capped at ₹2,00,000.

The new regime disallows almost all of these. It retains the standard deduction for salary and pension, the deduction for family pension, the employer's contribution to the National Pension System under Section 80CCD(2), and the employment-generation deduction under Section 80JJAA. It does not permit a loss under the head house property to be set off against other heads.

3. The break-even, and how to find yours

Because the new regime taxes a larger base at lower rates and the old regime taxes a smaller base at higher rates, there is always a level of deductions at which the two produce the same liability. Below that level the new regime wins. Above it, the old regime does.

The method is mechanical:

• Take gross total income for the year, including salary, house property, business and other sources
• List the deductions you will actually claim and can substantiate — not the ones you could theoretically claim
• Compute the liability under each regime on those figures, including cess and any surcharge
• Compare, and then ask the second question: is the difference large enough to justify locking up capital for the lock-in periods the old-regime deductions require?

That last point is the one most often skipped. A deduction under Section 80C obtained by committing ₹1,50,000 to a five-year instrument is not free. If the tax saved is modest and the capital would otherwise have earned a better return elsewhere, the old regime can win on tax and lose on outcome.

A regime is not chosen once. It is a computation repeated every year, because both the law and your own deduction profile move.The AKV working rule

4. Who still tends to benefit from the old regime

In practice, taxpayers who continue to compute lower under the old regime usually have several of the following at once, not just one:

• Interest on a self-occupied housing loan running near the ₹2,00,000 ceiling
• House rent allowance in a metropolitan city, at a rent high enough for the exemption to be substantial
• Section 80C fully used through provident fund, tuition fees, principal repayment and insurance already committed
• Health insurance premiums for both the family and dependent parents, particularly senior citizens
• The additional ₹50,000 National Pension System deduction under 80CCD(1B)

Taxpayers with income principally from business or profession, few personal deductions, or income concentrated at the top of the scale where the surcharge cap operates, will usually find the new regime lower.

5. The procedural trap

A taxpayer with no income from business or profession may choose between regimes each year, at the time of filing the return. A taxpayer with income from business or profession is in a different position: the election out of the new regime is made in Form 10-IEA, and it must be filed on or before the due date for the return under Section 139(1). The choice may then be reversed only once in the taxpayer's lifetime, after which the new regime applies permanently.

Two consequences follow. First, for a business taxpayer the decision is not a filing-season decision; it is a decision that must be taken and formally recorded before the due date. Second, a return filed late by such a taxpayer cannot carry a valid old-regime election, whatever the arithmetic would have shown.

6. Looking to FY 2026-27

Income earned from 1 April 2026 falls under the Income-tax Act, 2025, which takes effect for tax year 2026-27. The structure of the choice and the arithmetic described here should not be assumed to carry across unchanged. Where a decision spans the two years — a lock-in commenced now that runs into the new Act, for instance — the position under both statutes should be checked before the commitment is made.

A calculator for the current year is published on the firm's resources page. It is an estimate: it does not model surcharge, special-rate income or the full range of exemptions, and it is not a substitute for a computation on your actual figures.

This article is general commentary on the law as it stands and is not advice on any specific facts. Positions in tax, corporate and exchange-control law change with amendments, notifications and judicial decisions; please confirm the current position with the firm before acting.