Notice deemed to be valid in certain circumstances

523. (1) Where an assessee has appeared in any proceeding or co-operated in any inquiry relating to an assessment or reassessment, it shall be deemed that any notice under this Act, which is required to be served upon him, has been duly served upon him in time as per the provisions of this Act and such assessee shall be precluded from taking any objection in any proceeding or inquiry under this Act that the notice was— ( a) not served upon him; or ( b) not served upon him in time; or ( c) served upon him in an improper manner. (2) The provisions of sub-section (1) shall not apply where the assessee has raised such objection before the completion of such assessment or reassessment. 32. Substituted by the Finance Act, 2026, w.e.f. 1-4-2026. Prior to its substitution, section 522 read as under: “522. Return of income, etc., not to be invalid on certain grounds.— No return of income, assessment, notice, summons or other proceeding, furnished or made or issued or taken, or purported to have been furnished or made or issued or taken, in pursuance of any of the provisions of this Act, shall be invalid or shall be deemed to be invalid merely by reason of any mistake, defect or omission in such return of income, assessment, notice, summons or other proceeding, if such return of income, assessment, notice, summons or other proceeding is in substance and effect in conformity with or according to the intent and purposes of this Act.” Presumption as to assets, books of account, etc.