IMPORTANT: the Income-tax Act 2025 replaced the Income-tax Act 1961 from 1 April 2026, and this subject teaches the 2025 Act as the law in force. The 2025 Act replaces "previous year" and "assessment year" with a single "tax year". Old 1961 section numbers are given in brackets because judgments and past papers use them. Rates and slabs are set by each year’s Finance Act — check the current one.
The sections below are the ones the LL.B. papers examine on this Act, with the unit that covers each and the cases decided on it. The official text is on India Code ↗.