Rectification of mistakes: expanded deemed mistake rules allow tax authorities to amend assessments after specified events.
Section 154 authorises income tax authorities to rectify "mistakes apparent from the record" by amending orders and intimations, with procedural safeguards where liability is increased; time limits apply. Section 155 lists specific subsequent events that are to be treated as such mistakes, setting distinct limitation periods measured from those events and enabling AOs to recompute income or amend assessments accordingly. The Finance Act amendment expanding treatment of surcharge and cess disallowance is noted as an instance permitting recomputation without reopening assessment. (AI Summary)