A practical old-regime deduction guide for taxpayers mapping familiar 80C-style deductions to the new income-tax law references.

With the Income-tax Act, 2025 now in the picture, many taxpayers are navigating a transition that looks deceptively simple on the surface. The investments are the same — ELSS, EPF, life insurance premiums, tuition fees. The deduction logic is familiar. But the legal references have shifted, and filing without checking whether a familiar claim maps correctly to the new Act can create silent errors. This guide helps taxpayers and their advisers work through that mapping exercise for AY 2026-27.

This is an educational readiness note, not a promise of any tax outcome. Match every position against the official portal, notified forms, and the taxpayer's own documents.

What the transition changes in practice

The labelling of deductions has moved, but the proof discipline has not. Each deduction is still claim-specific: the taxpayer must confirm regime selection, eligible payment, documentary proof, applicable limit, and the correct schedule before claiming anything.

Point	Practical meaning
1	Deduction labels may change, but proof discipline still matters.
2	Old-regime selection should be compared against the new regime.
3	Taxpayers should not mix ineligible deductions into a new-regime return.

Why the timing creates a year-selection problem

Filing the FY 2025-26 return in AY 2026-27, Tax Year 2026-27 compliance obligations, old notices, and new forms can all land in the same month. Mixing these up — using a Tax Year 2026-27 reference for something that belongs in AY 2026-27 filing — is a common source of errors. A clean file should clearly show the period, the applicable law reference, the portal form used, the payment or return type, and the supporting evidence behind each figure.

Walking through a typical scenario

A taxpayer with ELSS investments, EPF contributions, life insurance premiums, and tuition fee payments faces a straightforward deduction checklist in theory. In practice, the question is whether each of those payments was made during FY 2025-26, whether the proof is in hand, and whether a quick comparison of old-regime versus new-regime tax liability has actually been run. Skipping the comparison before finalising the return is one of the more avoidable mistakes at this stage of filing.

Documents to have ready

80C-style proofs: investment statements, EPF passbook, premium receipts, tuition fee receipts
Health insurance premium receipts for any 80D-type claims
NPS account statement and employer NPS certificate if applicable
Regime comparison worksheet showing tax liability under both options

Map each deduction to its current schedule entry

List every intended deduction separately instead of relying on a combined investment total.
Match the claimant, payment date, payee, eligibility condition, and receipt for each item.
Confirm the current schedule and form field that corresponds to the deduction being claimed.
Reconcile the schedule total with the supporting proofs before filing.

Official references

Reference	Link
Income Tax Department - Income-tax Act, 2025 PDF	Open source
Income Tax Department - Budget 2025 income tax FAQs	Open source
Income Tax Department - New Act transition FAQs	Open source

Errors to watch for

Citing an old form number or section reference without verifying whether it still applies under the Income-tax Act, 2025.
Keep the Section 123 transition AY 2026-27 filing records separate from Tax Year 2026-27 payment and TDS records.
Accepting a headline slab or rebate figure without running the full computation.
Before completing Section 123 transition, reconcile AIS, Form 26AS, challans, books, and certificates.
Not keeping a note of the official source and the computation logic behind each decision.

How MyeCA can help

For a deduction carried into the new framework, start with the payment date, eligible person, permitted product or expense, and the document that proves each condition. Map that evidence to the notified return schedule before treating an older section reference as equivalent.

Before you submit

Confirm the year. Read the official source for each deduction. Collect supporting records. Write a short computation note. Verify the return or payment route. Save the acknowledgement once submitted. That sequence, run carefully, removes most of the risk in a transition-year return.

Deductions Under Section 123 and Schedule XV: 80C Transition Guide