(a) Action by proprietor. Where the proprietor wishes to defer payment of tax, he must execute an agreement on TTB Form 5110.51 to pay the amount of tax which has been computed and entered on the form. If a bond is required under § 26.66, he must certify, under the penalties of perjury, that he is not in default of any payment of tax chargeable against his bond, and that his bond is in the maximum penal sum, or that it is sufficient to cover the amount of tax on the distilled spirits described on the form in addition to all other amounts chargeable against this bond. If the proprietor deferring payment of tax is not required to provide a bond under § 26.66, the proprietor must certify under the penalties of perjury that the proprietor was liable for not more than $50,000 in taxes in the preceding calendar year, reasonably expects to be liable for not more than $50,000 during the current calendar year, and is not using the TTB Form 5100.21 for any shipment of distilled spirits for industrial use. The proprietor must deliver all copies of TTB Form 5110.51 and any package gauge record as provided in § 26.164a to the revenue agent.

(b) Action by revenue agent. On receipt of TTB Form 5110.51 and any package gauge record, the revenue agent shall verify the computation of the tax entered on the TTB Form 5110.51, and if the proprietor has on file a good and sufficient bond, TTB Form 5110.50, so indicate on TTB Form 5110.51. The revenue agent shall then execute his report of release on the TTB Form 5110.51 and release the spirits for shipment to the United States. He shall distribute TTB Form 5110.51 and any package gauge record according to the instructions of TTB Form 5110.51. Where the revenue agent finds that the proprietor does not have good and sufficient bond coverage, or where the revenue agent has received information that the proprietor is in default of payment of any taxes previously charged to his bond, he shall return all copies of TTB Form 5110.51 and any package gauge record to the proprietor, giving his reasons for such action.