Cancellation of registration for noncompliance or business cessation triggers recovery of input tax credit liabilities before deregistration. Section 29 empowers the proper officer to cancel registration where the business is discontinued, transferred, altered in constitution, where registration is no longer required, for prescribed contraventions, sustained non filing of returns, failure to commence after voluntary registration, or where registration was obtained by fraud, wilful misstatement or suppression of facts, subject to opportunity of being heard. Cancellation may be retrospective. Cancellation does not extinguish pre cancellation tax liabilities, and a cancelled registrant must pay, via electronic ledger, an amount equivalent to input tax credit on stock or capital goods or the output tax on those goods, calculated as prescribed.