Return filing obligation for exchanges and prescribed persons requires annual submission of returns for taxable securities transactions. Recognised stock exchanges and prescribed persons, including Mutual Funds, insurance companies, and lead merchant bankers, must prepare, verify and deliver prescribed returns to the Assessing Officer or authorised agency within prescribed timeframes, setting forth particulars of all taxable securities transactions in the financial year. Failure to furnish permits the Assessing Officer to issue a notice for submission within a further prescribed period, and assessee may file or revise a return at any time before assessment where omissions or wrong statements are discovered.