Clubbing of tax periods: restriction across financial years removed, permitting exporters to aggregate refund claims. Refund claims are tied to the relevant period chosen by the applicant rather than a statutory tax period; exporters may file monthly or quarterly refunds or club successive months/quarters, and the previous prohibition on clubbing periods across different financial years has been removed. Casual and non-resident taxable persons must claim any refundable amount in their last return after adjustment of advance tax deposited at registration.