27 CFR § 13.75
Evidence of receipt by TTB
April 24, 2020
If there is a time limit on TTB action that runs from TTB's receipt of a document, the date of receipt may be established by a certified mail receipt or equivalent written acknowledgment secured by a commercial delivery service or by a written acknowledgment of personal delivery. In the absence of proof of receipt, the date the document is logged in by TTB will be considered the date of receipt.