For most taxpayers the new regime vs old regime question for AY 2026–27 has one answer: the new regime saves more tax. Since Budget 2025 raised the Section 87A rebate to ₹60,000 and the standard deduction to ₹75,000, a resident individual pays no tax up to ₹12 lakh of taxable income, or ₹12.75 lakh of salary. The old regime only overtakes it once total deductions and exemptions run past roughly ₹8 lakh, which needs a large home loan, full HRA and every Chapter VI-A limit used together.

AY 2026–27 covers income earned in FY 2025-26, between 1 April 2025 and 31 March 2026, and it is the last assessment year governed by the Income-tax Act, 1961. Two dates matter more than the arithmetic. Salaried filers on ITR-1 and ITR-2 were due on 31 July 2026, and non-audit business and professional filers on ITR-3 and ITR-4 are due on 31 August 2026. Miss your date and the choice disappears, because a belated return cannot be filed under the old regime.

01What Is the Difference Between the New Regime vs Old Regime for AY 2026–27?

The old regime taxes a smaller income at higher rates after you subtract deductions. The new regime under Section 115BAC taxes a larger income at lower rates with almost nothing subtracted. That is the whole trade, and every comparison reduces to whether your deductions are large enough to beat the rate difference.

The new regime has been the default since AY 2024-25, so doing nothing means you are taxed under it. Choosing the old regime is an active step. A salaried person without business income makes that choice inside the return itself, every year. Anyone with business or professional income has to file Form 10-IEA separately before the due date, and can only return to the new regime once in a lifetime.

The other structural difference is the rebate. Under the new regime the Section 87A rebate is up to ₹60,000 and applies to total income up to ₹12 lakh. Under the old regime it remains ₹12,500 and applies only up to ₹5 lakh. That single gap decides the new regime vs old regime comparison for the large majority of middle-income filers before deductions are even considered.

02What Are the Income Tax Slabs for AY 2026–27 Under Both Regimes?

The income tax slabs AY 2026-27 uses under the new regime start at ₹4 lakh and rise in ₹4 lakh bands. A 4% health and education cess applies on top of the tax under both regimes.

The old regime keeps the structure it has had for years: nil up to ₹2,50,000, 5% from ₹2,50,001 to ₹5,00,000, 20% from ₹5,00,001 to ₹10,00,000 and 30% above ₹10,00,000. The basic exemption rises to ₹3,00,000 for resident senior citizens and ₹5,00,000 for those aged 80 and above, a concession the new regime does not offer. The old regime reaches its 30% rate at ₹10 lakh; the new regime does not reach it until ₹24 lakh, and that ₹14 lakh stretch is where the saving comes from.

Surcharge differs too. The highest surcharge rate under the old regime is 37% on income above ₹5 crore, while the new regime caps it at 25%. For very high earners this alone can outweigh every deduction available, which is why the income tax slabs AY 2026-27 sets out only tell part of the story.

03How Much Can You Actually Save Under Each Regime?

The honest answer depends on one number: your total deductions. Two worked examples show where the line sits.

Case 1 — Salary of ₹14,00,000, ordinary deductions

The taxpayer claims ₹1,50,000 under Section 80C and ₹25,000 under Section 80D, and pays no rent or home loan interest.

The new regime saves ₹89,700. Nothing about this case is unusual, and it is the position most salaried filers are in.

Case 2 — Salary of ₹24,00,000, everything claimed

The taxpayer claims HRA of ₹3,60,000, ₹1,50,000 under 80C, ₹50,000 under 80D, ₹50,000 under 80CCD(1B) and ₹2,00,000 of self-occupied home loan interest under Section 24(b).

The old regime wins by ₹7,020. That is the point worth sitting with: after claiming ₹8,60,000 of deductions and exemptions, the advantage is under ₹600 a month. At this income the break-even sits at roughly ₹8,37,500 of total old tax regime deductions. Below that figure the new regime is cheaper, and most people are well below it.

04What Deductions Can You Still Claim in the New Tax Regime?

The list of new tax regime deductions is short but not empty, and the ones that survive are worth using. The standard deduction under the new regime is ₹75,000 for salary and pension income, against ₹50,000 in the old regime. Anyone weighing new tax regime deductions against the old list should start from that ₹25,000 head start.

• 1 Employer contribution to NPS under Section 80CCD(2) — up to 14% of salary, against 10% in the old regime. This is the single largest deduction still available, and it needs your employer to restructure the salary rather than anything you do at filing.
• 2 Deduction on family pension — ₹25,000, up from ₹15,000.
• 3 Section 80JJAA — deduction for the cost of new employees, relevant to business filers.
• 4 Section 80CCH — contribution to the Agniveer Corpus Fund, one of the few new tax regime deductions added after Section 115BAC was first drafted.
• 5 Interest on a let-out property under Section 24(b), set off against that property's rental income.

What goes is the familiar list: Section 80C, 80D, 80TTA and 80TTB, HRA under Section 10(13A), leave travel allowance, interest on a self-occupied home loan, 80G donations and 80E education loan interest. Old tax regime deductions of that kind are the entire reason anyone still opts out, and they now have to add up to a very large number before it pays. The standard deduction under the new regime is the only one of the familiar reliefs that carries across untouched.

05Which Tax Regime Is Better for Salaried Employees in AY 2026–27?

The better tax regime for salaried employees is the new one in almost every case below ₹20 lakh of gross salary, and in most cases above it too. The reason is the rebate: at ₹12.75 lakh of salary the tax is nil under the new regime, and matching that under the old regime would need taxable income pushed down to ₹5 lakh, which takes over ₹7 lakh of deductions on a ₹12.75 lakh salary.

The table below shows how much you would need in total old-regime deductions, including the ₹50,000 standard deduction, before the old regime becomes the cheaper option. Anything less than the figure shown means the new regime wins.

The ₹12.75 lakh row is the hardest bar of all, because the new regime charges nothing at that salary and the old regime can only match zero by pushing taxable income down to ₹5 lakh. The requirement then eases at ₹15 lakh before climbing again, which is the shape the Section 87A rebate cliff creates. Across the whole table the honest summary of the new regime vs old regime maths is that the old regime needs six to eight and a half lakh of deductions to be worth choosing.

The question of which tax regime is better turns practical above ₹20 lakh, and only for a specific profile: a taxpayer paying substantial rent in a metro, servicing a home loan at the full ₹2 lakh interest cap, and using 80C, 80D and the NPS deduction to their limits. Someone who fits all of that should run the numbers rather than assume. Everyone else is choosing between a small loss and a large one, and the gap between the two widens as income rises.

06How Do You Choose and Switch Between Regimes for AY 2026–27?

The mechanics differ depending on whether you have business income. These six steps cover the regime decision within ITR filing AY 2026-27, from computation to verification.

• 1 Compute your tax under both regimes before you file. Settle the new regime vs old regime question on actual figures from Form 16, the AIS and your investment proofs rather than last year's assumption. The calculator on the Income Tax e-filing portal handles both regimes and takes a few minutes.
• 2 Establish whether you have business or professional income. This determines the entire process. Salary, pension, house property, capital gains and other sources do not count. Income under Section 44AD or 44ADA does, even where it is presumptive and small.
• 3 If you have no business income, choose inside the return. Select the opt-out option in ITR-1 or ITR-2 and file before the due date, since for these forms ITR filing AY 2026-27 carries the regime choice itself. No separate form is needed, and the choice is yours again next year with no restriction on switching back and forth.
• 4 If you have business income, file Form 10-IEA first. Submit it on the e-filing portal before the Section 139(1) due date, note the acknowledgement number, and quote that number in ITR-3 or ITR-4. Form 10-IEA filed after the due date does not give a valid old-regime option for that year.
• 5 Understand the one-time restriction on business income. Once you opt out through Form 10-IEA, the old regime continues for later years until you file a second Form 10-IEA to re-enter the new regime. That withdrawal can be exercised once. After it, you cannot go back to the old regime for as long as you have business or professional income.
• 6 File and e-verify within the due date. A return uploaded but not verified within 30 days is treated as never filed, which pulls you into belated territory and cancels the regime choice you just made. Aadhaar OTP at the point of submission closes this out immediately.

07What Happens If You File a Belated Return for AY 2026–27?

A belated return AY 2026-27 costs money, options and flexibility, and it removes the regime choice entirely. The Section 234F fee is ₹5,000, reduced to ₹1,000 where total income does not exceed ₹5 lakh, and no fee applies where income is below the basic exemption limit. Interest under Sections 234A, 234B and 234C runs separately on any unpaid tax, so a belated return AY 2026-27 is filed with a bill attached.

The larger costs are structural. The old regime becomes unavailable, so a taxpayer with genuine deductions loses them entirely. Business and capital losses cannot be carried forward, though house property loss survives. Refunds take longer. The belated return window for AY 2026–27 closes on 31 December 2026, after which only an updated return under Section 139(8A) remains, within four years of the end of the assessment year.

If you are already past your due date, the practical question is damage control rather than regime selection. File the belated return AY 2026-27 requires before 31 December 2026 and pay the fee, because the alternative is an updated return with additional tax on top. Compute the liability under the new regime and pay any shortfall promptly, since interest under Section 234A runs from the due date until you file. Losses that cannot be carried forward are gone, but nothing is served by delaying further.

Filing on time and getting the regime wrong is a smaller problem than filing late. A revised return under Section 139(5) is available until 31 March 2027 for AY 2026–27, and it can correct figures within the regime you validly chose. Claiming old-regime deductions in a belated return usually produces a Section 143(1)(a) adjustment denying them, followed by a demand.

08How Have India's Tax Regimes Changed Since 1991?

India's personal tax system has moved from punitive rates with heavy shelter to moderate rates with almost none. Before 1991 the structure was built on the opposite logic to today's. Marginal rates peaked above 90% in the 1970s across a dozen slabs, and because so much income was taxed away at the top, the deduction and exemption architecture existed mainly to make the rates survivable. Saving tax and saving money were the same activity.

Liberalisation reversed that. The 1992-93 budget cut the structure to three slabs, and the 1997-98 budget set rates at 10%, 20% and 30%, roughly where the old regime still sits nearly three decades later. Rates fell but the deduction architecture stayed, which is how India ended up with moderate headline rates and one of the more complicated personal tax computations anywhere.

Section 115BAC, introduced by the Finance Act, 2020, was the attempt to unwind that. It offered lower rates to anyone willing to give up deductions, was optional and largely ignored, then became the default from AY 2024-25. The Finance Act, 2025 made it decisively cheaper for most people by lifting the rebate to ₹60,000 and the standard deduction to ₹75,000. From 1 April 2026 the Income-tax Act, 2025 replaces the 1961 Act and swaps "previous year" and "assessment year" for a single "tax year", though the rates and both regimes carry over unchanged. AY 2026–27 is the last year filed under the old statute.

09Frequently Asked Questions About the New Regime vs Old Regime

10The Bottom Line

For most salaried taxpayers, the new regime vs old regime decision for AY 2026–27 is not close: the Section 87A rebate and the ₹75,000 standard deduction put nil tax within reach up to ₹12.75 lakh of salary, and the old regime only closes that gap once deductions run into the ₹6–8.5 lakh range. Run both computations before you file rather than repeating last year's choice — the numbers move every time your salary structure, home loan, or investment mix changes, and the calculator on the income tax portal takes minutes to confirm which way you land.

What doesn't move is the deadline discipline: business filers need Form 10-IEA filed and acknowledged before the due date, and everyone loses the old regime the moment a return turns belated. Casela Advisors is a Mumbai-based chartered accountancy firm serving startups, SMEs, corporates and NRIs across India and overseas, advising on audit and assurance, income tax and GST, ROC and FEMA compliance, company formation, NRI taxation and virtual CFO support.