Old vs New Tax Regime: The ₹12 Lakh Maths Nobody Shows You

Everyone quotes the ₹12 lakh number. Almost nobody runs it#

Since February 2025, "no tax up to ₹12 lakh" has been repeated often enough that most salaried Indians treat it as settled and stop thinking. Central Board of Direct Taxes data suggests about 88 per cent of individual taxpayers had moved to the new regime by last year's filing season, up from roughly 74 per cent when the slabs were announced.

Most of them are right to have moved. A minority are not, and a smaller group has walked into a band of income where earning more leaves them with less.

Budget 2026 touched none of this. The Finance Minister kept the rates under both regimes unchanged for FY 2026-27, so the arithmetic below is not a forecast. It is the tax on the salary you are drawing now.

The two regimes, stripped down#

Both regimes tax the same income. They differ on the rate ladder and on what you may subtract before climbing it. The new regime, historically section 115BAC and now section 202 of the Income-tax Act, 2025 since the new Act took effect on 1 April 2026, offers seven slabs and almost no deductions. The old regime offers four slabs, higher rates, and the familiar cupboard of tax breaks.

A 4 per cent cess applies in both. Slab figures come from the Income Tax Department's page for salaried individuals, the ₹75,000 standard deduction from Budget 2025, and the 80CCD(2) ceiling of 14 per cent for private employees from July 2024.

Three words get muddled constantly. A deduction reduces the income you are taxed on. A rebate reduces the tax itself, after it is calculated. Cess is 4 per cent charged on whatever tax survives the rebate. That last point does more damage than people expect.

At ₹12 lakh, the old regime cannot win#

Take a salaried person on ₹12,00,000 a year.

New regime: subtract the ₹75,000 standard deduction for taxable income of ₹11,25,000. The slabs produce ₹52,500 of tax, and the ₹60,000 rebate under section 87A wipes it out. Tax payable: nil.

Old regime: nil requires taxable income of ₹5,00,000 or less, because that is where the old rebate stops. After the ₹50,000 standard deduction you must find ₹6,50,000 of further deductions, or 54 per cent of gross salary.

Stack every common deduction to its ceiling: ₹1,50,000 under 80C, ₹50,000 under 80CCD(1B) for NPS, ₹25,000 under 80D for health cover, and ₹2,00,000 of home loan interest on a self-occupied house. That is ₹4,25,000, and it assumes you have a loan, an NPS account and spare cash. You are still ₹2,25,000 short, with ₹59,800 to pay.

At ₹12 lakh the answer is not "it depends". Unless you also pay heavy metro rent or unusually large medical premiums, the new regime wins comfortably.

The ₹12.75 lakh cliff, and the band where a rupee costs 1.04 rupees#

Salary of ₹12,75,000: the standard deduction leaves ₹12,00,000, the rebate applies in full, tax is nil. Salary of ₹13,00,000: taxable income is ₹12,25,000, the rebate vanishes, and slab tax jumps to ₹63,750.

Parliament saw that cliff and built a ramp. Where total income crosses ₹12,00,000, marginal relief caps tax at the amount by which income exceeds the threshold. Go ₹25,000 over the line and you pay ₹25,000, not ₹63,750.

Inside that band your marginal rate is 100 per cent, and the 4 per cent cess is then added to the relieved figure, as calculators and practitioners apply it. So ₹25,000 becomes ₹26,000.

Relief stops working at taxable income of about ₹12,70,588, where ordinary slab tax finally falls below the excess over ₹12 lakh. For a salaried filer that is gross pay of roughly ₹13,45,588.

So if your salary sits between about ₹12.75 lakh and ₹13.46 lakh, every additional rupee of taxable income is taken, plus four paise. A ₹30,000 increment in that zone leaves you with less cash than before. Not a loophole or a drafting error, just what a rebate cliff plus a cess on the relieved amount produces. No appraisal letter mentions it.

The one lever inside the new regime is your employer's NPS contribution under 80CCD(2), which survives up to 14 per cent of salary and cuts taxable income.

Where the old regime still wins: the break-even line#

The old regime is not dead. It turns competitive at a level of deductions that is high but not fantastical, and that threshold moves with income in a way most comparisons miss.

Computed from the slab, rebate, standard deduction and cess rules the department publishes for salaried individuals, assuming no surcharge, which starts above ₹50 lakh.

The dip at ₹15 lakh is the interesting bit. That is where the old regime is easiest to justify, needing "only" about ₹5.44 lakh of deductions. Add HRA of a little over ₹1 lakh to the ₹4.25 lakh stack and a metro renter with a full 80C clears it. Above ₹20 lakh the bar climbs past ₹7 lakh, and the old regime becomes a game for people with very large housing interest or heavy medical premiums.

One caution about that stack. Claiming ₹1.5 lakh under 80C means parting with ₹1.5 lakh, usually into a five-year lock-in, to save ₹45,000 at the 30 per cent rate. If you would not have invested anyway, the regime comparison and the investment decision have quietly become the same question. That is how people end up holding policies they never wanted.

If you are self-employed, the rules differ#

Three things change for freelancers, consultants and small business owners.

There is no standard deduction on business or professional income, so the threshold is ₹12,00,000 of total income, not ₹12,75,000. The extra ₹75,000 belongs to salary.

Presumptive taxation reshapes the problem before the regime question arises. Under section 44ADA, a resident professional with gross receipts up to ₹50 lakh, or ₹75 lakh where cash receipts stay within 5 per cent, declares half of receipts as profit. Section 44AD does the same for businesses at 8 per cent of turnover, or 6 per cent on digital receipts. A consultant billing ₹24 lakh largely by bank transfer declares ₹12 lakh of profit and lands on the rebate line.

The switching rules are asymmetric, and that is the costly one. A taxpayer without business income may choose afresh every year in the return itself. A taxpayer with business or professional income must file Form 10-IEA to opt out, and may opt out once and return once. After that the door locks. A salaried employee can experiment; a shopkeeper gets one round trip in a working lifetime.

One trap catches everyone. The relief was announced for income "other than special rate income such as capital gains", and the rebate cannot be set against tax on such income even though it still forms part of total income for the threshold test. Someone with ₹11 lakh of salary and ₹1.5 lakh of share gains is over the line and gets no rebate.

Key takeaways#

1. At a ₹12 lakh salary the new regime pays nil, and matching that under the old regime needs ₹6.5 lakh of deductions, or 54 per cent of gross pay. A maxed-out stack still leaves ₹59,800 payable.
2. Marginal relief taxes income between ₹12,00,000 and about ₹12,70,588 at an effective 100 per cent, and the 4 per cent cess on top makes each extra rupee cost 1.04 rupees.
3. The break-even deduction line moves: about ₹5.44 lakh at a ₹15 lakh salary, the old regime's most winnable point, rising towards ₹8 lakh above ₹25 lakh.
4. Self-employed filers get no standard deduction, so their threshold is ₹12 lakh, and Form 10-IEA allows one exit from the new regime and one return.
5. Deductions are spending, not saving. A ₹1.5 lakh 80C claim saves ₹45,000 at the top old rate, so the money must be worth committing on its own merits.

Frequently asked questions#

Is the new regime automatic? Yes, and it has been the default since AY 2024-25. To use the old regime you must actively choose it: in the return if you have no business income, through Form 10-IEA if you do.

Does "no tax up to ₹12 lakh" apply to my CTC? No. It applies to total income after the standard deduction and any allowed deduction. Employer PF and gratuity provision sit inside CTC but are not all taxable salary, so the two figures rarely match.

I earn ₹13 lakh. Should I ask for a smaller raise? That is between you and your employer, and this is not advice. What the arithmetic shows is that between roughly ₹12.75 lakh and ₹13.46 lakh of salary, extra taxable income does not raise take-home pay. A larger employer NPS contribution under 80CCD(2), where your organisation permits it, cuts taxable income without cutting what is set aside for you.

Can I switch regimes every year? Only if you have no business or professional income. With business income you may leave the new regime once and return once, then you are locked in.

Does the old regime still suit senior citizens? Sometimes. Basic exemption is ₹3 lakh at 60 and ₹5 lakh at 80 under the old regime, against a flat ₹4 lakh for everyone in the new one, and 80D limits for senior health cover are higher. It turns on the medical premium and interest income, so it needs computing individually.

Glossary#

Total income. What is left after every permitted deduction. Slabs apply to this figure, not to gross salary or CTC.

Standard deduction. A flat subtraction from salary income needing no proof or spending: ₹75,000 in the new regime, ₹50,000 in the old.

Rebate under section 87A. A reduction of the tax itself rather than the income. ₹60,000 in the new regime up to ₹12 lakh of total income, ₹12,500 in the old up to ₹5 lakh.

Marginal relief. A cap stopping tax from exceeding the amount by which income crosses a threshold, so a rupee over ₹12 lakh does not trigger the whole ₹60,000 bill.

Form 10-IEA. The form a taxpayer with business or professional income files to leave the new regime, and again to come back.

Special-rate income. Income such as capital gains taxed at its own rate rather than at slab rates, against which the 87A rebate cannot be set off.

A note on scope#

This shows how the two regimes compute tax at stated income levels. It is general information, not tax or investment advice. Every calculation assumes a resident individual below 60 with no capital gains, and ignores surcharge, which begins above ₹50 lakh. If your position involves capital gains, foreign income or a business under audit, a chartered accountant costs less than the mistake.

References#

1. Income Tax Department, Salaried Individuals for AY 2026-27: slabs, rebate, surcharge and cess
2. Income Tax Department, FAQs on New Tax Regime vs Old Tax Regime: default regime, Form 10-IEA and switching rules
3. Income Tax Department, What is rebate under section 87A for FY 2025-26 and who can claim it, including marginal relief
4. Income Tax Department, Deductions: limits under sections 80C, 80CCD(1B), 80CCD(2), 80D and 80E
5. Income Tax Department, Computation of tax for individuals: basic exemption limits and rebate treatment
6. Income Tax Department, Tax on presumptive basis: sections 44AD and 44ADA thresholds and rates
7. Press Information Bureau, No income tax on annual income up to ₹12 lakh under the new tax regime, 1 February 2025
8. Business Today, Tax slabs FY 2026-27: what Budget 2026 changed for individual taxpayers, 1 February 2026
9. Business Today, Section 115BAC becomes section 202 under the new Income Tax Act, 18 February 2025
10. Business Today, Employer NPS contribution limit for the private sector raised to 14 per cent from 10 per cent, 23 July 2024
11. Business Today, CBDT chairman Ravi Agarwal on new regime adoption and the ₹12 lakh threshold, 3 February 2025
12. Newsd, New tax regime becomes top choice for most income tax filers in 2026, citing CBDT data of about 88 per cent adoption, 23 July 2026
13. FinCalC, Marginal relief in the new tax regime, including the ₹12,70,588 cut-off and cess treatment
14. TaxGuru, No section 87A rebate against tax on short-term capital gains under section 111A, though such income counts in total income