Claim for refund of excise duty requires timely application and Commissioner satisfaction for payment or Fund credit. Section 11B requires a claimant seeking refund of excise duty and any interest to apply to the Assistant or Deputy Commissioner with prescribed evidence within the relevant limitation period (one year, except where duty is paid under protest). The Commissioner may order credit of refundable amounts to the Fund or, where relatable to specified categories (export rebates, unspent advances, input credit refunds, duty borne by manufacturer or buyer not passed on, or classes notified by Central Government), may pay the amount to the applicant. Refunds are permitted only as per subsection (2); notifications adding classes require parliamentary laying and approval and may be rescinded.