Income Tax Act 2025 Section Mapping: Old vs New Section Numbers

If you've filed taxes in India before, a few section numbers probably live in your head permanently — 80C for tax-saving investments, 80D for health insurance premiums, 44AB for tax audits. From Tax Year 2026-27 onward, all of that muscle memory needs an update. The rules and limits behind these sections haven't changed — only where they live in the statute has.

Key Section Mapping Table

Old Section (1961 Act)	What It Covers	New Section (2025 Act)
Section 80C	Tax-saving investments (LIC, PPF, ELSS, tuition fees, etc.)	Section 123
Section 80D	Health insurance premium deduction	Section 126
Section 44AB	Tax audit provisions	Section 63
Section 10	Income exemptions (HRA, gratuity, leave encashment, etc.)	Schedule II
Section 115BAC	New (concessional) tax regime	Section 202
Section 195	TDS on payments to non-residents	Section 393

This covers the sections most commonly referenced by individual taxpayers. The full Act remaps all 819 sections of the old law into 536 sections — for a complete list, a CA or an official CBDT mapping utility is the more reliable reference than any single guide.

What Stayed the Same Behind Each Number

This is the part worth remembering: the deduction limits and eligibility rules attached to these sections carried over unchanged. Section 80C's ₹1.5 lakh cap and its eligible investment categories are identical under Section 123 — only the citation changed. The same applies to Section 80D's ₹25,000/₹50,000 limits, now under Section 126.

Notable Structural Shifts

Section 10 moved to a Schedule, not a section. All the income exemptions that used to sit under Section 10's many sub-clauses (10(13A) for HRA, for example) are now organized under Schedule II — a structural change, not a substantive one. The exemptions themselves are preserved.

Old-style suffixed sections are gone. Numbers like 80CCC, 80CCD, and 80CCE — with their alphabetical suffixes — are replaced by a clean sequential numbering system. Every section is now a plain number, without the letters that made older references hard to say or search for.

Forms changed too. Forms 15CA and 15CB (used for foreign remittance reporting) have been replaced by new Forms 145 and 146 under the accompanying Income-tax Rules, 2026.

What This Means for Your Documents

If you maintain personal records, investment declarations, or old ITR filings that reference old section numbers, you don't need to update historical documents — filings from before April 1, 2026 remain valid under the old numbering. Going forward, new declarations, employer tax computation sheets, and notices issued after April 1, 2026 will use the new section numbers.

Common Mistakes

1. Assuming old section numbers are invalid. Old filings and documents referencing Section 80C, 44AB, etc. remain valid for the years they were filed under — you're not required to retroactively update anything.

2. Confusing renumbering with removal. A section number changing doesn't mean the provision itself was removed — nearly every familiar deduction and exemption from the old Act exists somewhere in the new Act, just under a different number.

Key Takeaway: Section numbers changed across the board — 80C is now 123, 80D is now 126, and Section 10's exemptions moved to Schedule II — but the underlying deduction limits and eligibility rules are unchanged. Want to know exactly which date each version applies to your filing? See Key Dates & Transition Rules.

Frequently Asked Questions

What is the new section number for Section 80C?

Section 80C is now Section 123 under the Income Tax Act, 2025. The ₹1.5 lakh deduction cap and eligible investments are unchanged.

Do I need to use the new section numbers on my FY 2025-26 return?

No — your ITR for FY 2025-26 income (filed by July 31, 2026) uses the old 1961 Act's section numbers. New numbers apply from Tax Year 2026-27 returns onward.

Where can I find the complete mapping for a specific section not listed here?

For a comprehensive list beyond commonly-used sections, a chartered accountant or an official CBDT section-mapping reference is more reliable than any single third-party summary, given the scale of the 819-to-536 remapping.

Did any deduction amount actually change, not just the section number?

For the sections referenced here, no — the underlying limits and eligibility criteria carried over as-is. The new Act is a structural and numbering reform, not a policy change to these specific provisions.