Registration validity for casual and non-resident taxable persons limited, with officer-granted extension possible and advance deposit required. Special provisions govern registration and financial prerequisites for casual and non-resident taxable persons: the certificate of registration is limited to the period specified in the application or a statutory duration, supply of taxable goods/services is permitted only after issuance, and the proper officer may grant a discretionary extension for sufficient cause. Applicants must make an advance deposit equal to estimated tax liability for the registration period, deposit additional amounts for any extension, and deposited sums are credited to and utilised from the electronic cash ledger.