Old vs New Income Tax Regime in India: How to Compare Your Tax Liability

Compare tax regimes by calculating taxable income and final liability separately under each set of rules. Do not compare only headline slab rates or assume every deduction works in both regimes. This guide uses the Income-tax Act, 2025 as amended by Finance Act, 2026; later changes and taxpayer-specific conditions still require checking before filing or publication as current tax advice.

Identify the correct year and legal framework

The Income Tax Department's transition FAQ explains that income earned from 1 April 2026 falls under the Tax Year terminology of the 2025 Act. AY 2026–27 relates to the earlier period under the 1961 Act, so the two labels must not be used interchangeably.

Distinguish the old tax regime from the old Act. Both regime choices can exist within the new legal framework. Familiar section numbers from older guides may have changed; the new-regime provision checked here is section 202, while the rebate provision is section 156.

Record residency, age, income sources, business status and the applicable year before calculating. Special-rate income, agricultural income and losses can require additional logic beyond a salary-only worksheet. This article is not a complete return-preparation calculator.

Load the rates and allowable adjustments

Under section 202 in the official amended Act, new-regime bands are nil to ₹4 lakh, then 5%, 10%, 15%, 20% and 25% on successive ₹4 lakh bands, and 30% above ₹24 lakh.

For an under-60 individual under the general old-regime schedule, the Finance Act, 2026 provides nil to ₹2.5 lakh, 5% to ₹5 lakh, 20% to ₹10 lakh and 30% above that. Resident senior categories have different general thresholds; do not apply the under-60 table universally.

The amended Act's salary standard deduction is up to ₹75,000 under section 202 and ₹50,000 otherwise, limited by salary. Other exemptions and deductions need separate eligibility checks. A claimed amount is not automatically allowable merely because an employee included it in a declaration.

Work through one salary-only comparison

Assume a hypothetical resident under 60 with ₹15 lakh salary, no other income and no surcharge situation. Assume ₹1.5 lakh of additional deductions has been independently confirmed as allowable under the old-regime calculation and is unavailable in the new-regime case.

Old-regime taxable income is 1500000-50000-150000, or ₹13 lakh. Slab tax is ₹12,500 plus ₹1,00,000 plus ₹90,000, totalling ₹2,02,500. With 4% health and education cess, the illustrative liability is ₹2,10,600.

New-regime taxable income is 1500000-75000, or ₹14.25 lakh. Slab tax is ₹20,000 plus ₹40,000 plus ₹33,750, totalling ₹93,750. With 4% cess, the illustrative liability is ₹97,500. No rebate is assumed at this income level. The difference is ₹1,13,100 under these specific inputs, not a universal saving.

Build controls around the comparison

Use one row for each income source and deduction, with separate old and new columns. For every slab, compute MAX(0,MIN(taxable_income,upper_limit)-lower_limit)*rate, with appropriate treatment of the final open band. Sum the bands before applying the relevant rebate, relief, surcharge and cess.

Section 156 provides a resident-individual rebate framework, including the ₹12 lakh new-regime threshold and marginal relief conditions. Special-rate income needs particular care: do not turn a rebate headline into a statement that every person with income below a threshold owes no tax under all circumstances.

Show tax withheld separately from total liability. A refund means payments exceeded the final liability; it does not prove that the chosen regime produced the lowest tax. Compare final liabilities before adjusting for payments and credits.

Regime election rules differ with business or professional income, so verify forms, deadlines and switching restrictions. The examples were checked arithmetically but no return was filed or official calculator tested. Recheck post-Finance-Act amendments, notifications and individual deductions before using the worksheet for an actual taxpayer.

Quick questions, clear answers

Does the new regime forbid every deduction?

No. The permitted set differs, and the salary standard deduction is one important example. Check each item under current provisions rather than applying a blanket statement. Employer contributions, exemptions and other adjustments can have specific conditions that a generic comparison misses.

Is a payroll declaration the final regime choice?

Do not assume so. Withholding arrangements and the valid return-level election are related but distinct. Verify the current procedure for your income category, especially where business or professional income creates different conditions. Keep supporting records even if the employer accepted the declaration.

Should I invest only to make the old regime cheaper?

Compare the investment's purpose, liquidity, costs and risks as well as any tax effect. Spending or locking money solely to obtain a deduction can leave the household worse off. Calculate the incremental tax saving from an eligible action rather than treating the deduction amount as cash saved.

About this guide

Aniket Thakur prepared this educational guide from secondary research checked on 23 October 2026. All numerical illustrations are hypothetical unless stated otherwise. No investment product was tested, and no individual financial circumstances were assessed. Read the cited primary material and relevant product documents before acting.