The new tax regime is now the default. If you do nothing, you are taxed under it. That single change matters more than most of the slab adjustments, because it means the burden has shifted: you must now actively opt out to claim deductions, rather than actively opt in.

What each regime gives you

The new regime offers wider slabs, lower rates and a standard deduction of ₹75,000 for salaried taxpayers. In exchange you give up almost every deduction — 80C, 80D, HRA, LTA, and home loan interest on a self-occupied property.

The old regime has narrower slabs and higher rates, but permits the full deduction set: 80C up to ₹1.5 lakh, 80CCD(1B) for another ₹50,000, 80D for health insurance, HRA exemption, home loan interest up to ₹2 lakh under Section 24(b), and a ₹50,000 standard deduction.

The one number that decides it

Everything reduces to a single comparison: how much can you actually deduct under the old regime?

There is a break-even level of total deductions. Below it, the new regime's lower rates win. Above it, the old regime's deductions win. As a working guide, taxpayers who can claim roughly ₹4 lakh or more in total deductions tend to come out ahead under the old regime, and those below that generally do better under the new one.

The break-even shifts with income level, so treat this as a screening test rather than a verdict.

Who each regime suits

The new regime usually wins if you:

  • Rent your home in a city with modest rent, or live in company accommodation
  • Have no home loan
  • Invest little in 80C instruments beyond your EPF
  • Are early in your career with few commitments
  • Want to avoid locking money into 80C products purely for tax reasons

The old regime usually wins if you:

  • Pay a home loan EMI with substantial interest — this is often the single largest deduction
  • Pay high metro rent and claim a large HRA exemption
  • Already use the full ₹1.5 lakh of 80C, plus ₹50,000 in NPS
  • Pay significant health insurance premiums for yourself and elderly parents
  • Claim education loan interest under Section 80E

The deductions people forget to count

Before concluding that the new regime suits you, check whether you are undercounting:

  • Section 80D — health insurance premiums, with an enhanced limit for senior citizen parents. Frequently overlooked and often substantial.
  • Section 80E — education loan interest, with no upper cap, for up to eight years.
  • Section 24(b) — home loan interest up to ₹2 lakh on a self-occupied property. On a let-out property the treatment differs.
  • HRA — the exemption is the least of three formulas, not simply the rent you pay. Many people estimate it far too low.
  • Section 80CCD(2) — employer NPS contribution. Notably, this one is available in both regimes.
  • Section 80TTA/80TTB — savings account interest, with a higher limit for senior citizens.

Working out your own answer

  1. Take your gross annual salary.
  2. Add up every deduction you can genuinely claim under the old regime — not what you could theoretically claim if you restructured your finances, but what applies today.
  3. Compute tax under the old regime: gross, minus ₹50,000 standard deduction, minus your deductions, then apply old slabs.
  4. Compute tax under the new regime: gross, minus ₹75,000 standard deduction, then apply new slabs.
  5. Compare. Add 4% health and education cess to both.

Do this in April, not in January. The regime choice affects what you invest in all year, and discovering in March that you should have been in the old regime leaves you scrambling to deploy ₹1.5 lakh in a fortnight.

Switching between regimes

Salaried taxpayers without business income may switch each financial year when filing. Taxpayers with business or professional income face a far more restrictive rule — the switch back is generally a once-in-a-lifetime option. If you have business income, take advice before changing.

Separately, the regime you declare to your employer at the start of the year governs TDS. You can still choose the other regime when you file your return, but you will either have had excess tax deducted or face a shortfall.

The trap in optimising for tax alone

Choosing the old regime and then buying poor products to fill the ₹1.5 lakh is a common and expensive mistake. A five-year tax-saver FD returning a fully taxable 6.5%, or an endowment policy returning 4-5% for twenty years, can cost more in foregone returns than the tax you saved.

If the old regime suits you, use it with instruments you would want anyway — ELSS, PPF, NPS, term insurance premiums, your existing home loan principal. If the only way to justify the old regime is to buy products you would otherwise avoid, that is your answer.

Slabs, limits and deduction rules stated here apply to FY 2025-26 and are revised in each Union Budget. Verify current provisions, and book a consultation for a calculation against your own figures.