Input tax credit entitlement preserved on registration, status change or transfer subject to prescribed reversals and conditions. Section 18 allows input tax credit for registered persons in special circumstances: registration granted within prescribed time, registration under specified provision, cessation of composition status, or when an exempt supply becomes taxable - in each case credit for inputs, stock and capital goods held immediately before the change, subject to prescribed percentage reductions for capital goods. Credit claims are barred after one year from invoice. On change of constitution, unutilised credit may be transferred as prescribed. Opting into composition or becoming exempt triggers payment from electronic ledgers equal to attributable credit, calculated as prescribed. Disposal of capital goods requires reversal equal to the higher of reduced credit or tax on transaction value.