Tax Year replaces Assessment Year
The most confusing pair of words in Indian tax is gone. What that means in practice, and what it does not mean.
For sixty years, Indian taxpayers have carried two labels for what is essentially one thing. Income earned in the Previous Year was assessed in the Assessment Year, one year later. Income earned in FY 2024-25 was taxed in AY 2025-26. Two years, one set of income, and a steady supply of errors on challans and returns where the wrong one was entered.
The Income-tax Act, 2025 replaces both with a single term: Tax Year.
What it is
A Tax Year is the twelve-month period from 1 April to 31 March. Income earned in Tax Year 2026-27 is filed and assessed as Tax Year 2026-27. There is no separate year label for the assessment.
Where a business is newly set up during a year, or a source of income first comes into existence during a year, the tax year begins on that date and ends on the last day of that financial year.
What it is not
It is not a change to your accounting year. The 1 April to 31 March period is unchanged, so no business needs to alter its financial statements or books because of this.
It is not a change to when assessment happens. Income of a Tax Year continues to be assessed after that year ends, exactly as before. The sequence is identical; only the labelling changed.
It is not retrospective. FY 2025-26 is still FY 2025-26, still assessed in AY 2026-27, still under the 1961 Act.
Where it will actually bite
Not on the return. On everything around the return. Every ERP configuration with an assessment year field, every reconciliation template, every audit working paper, every internal checklist that asks a junior to enter the AY. Those need updating, and the ones that get missed will produce mismatched challans that take longer to correct than they took to create.
If your finance team has spent twenty years speaking in AY, the vocabulary change is the easy part. Finding all the places the old vocabulary is hard-coded is the work.
This note is general information. It is not professional advice, and the position may have changed by notification since it was written. If it touches something you are dealing with, write to us and we will look at your facts.