Audit by tax authorities requires advance notice, access to records and may lead to proceedings for unpaid taxes. The Commissioner or an authorised officer may audit a registered person, at business premises or office, after giving advance notice. The officer may inspect books, require information and assistance, and must complete the audit within a prescribed period subject to a written extension. Audit commencement is when requested records are made available or audit actually begins. On conclusion the proper officer must inform the registered person of findings, reasons and rights; detection of unpaid or erroneously refunded tax or wrongly availed input tax credit may lead to initiation of statutory recovery or assessment proceedings.