Audit by tax authorities can prompt assessment action for undisclosed tax liabilities and incorrect input tax credits. The Commissioner or an authorised officer may audit any registered person at the business premises or office after giving at least fifteen working days' notice; the officer may inspect records, require facilities and information, and must complete the audit within three months (extendable for recorded reasons). On conclusion the proper officer must notify the registered person of findings, rights, obligations and reasons within thirty days, and detection of tax shortfalls or incorrect input tax credit permits initiation of assessment or recovery proceedings.