27 CFR § 46.9
Time for filing claim
April 24, 2020
No credit or refund of any amount of tax to which the provisions of this subpart apply shall be made unless the claimant files a claim therefor within the time prescribed by law and in accordance with the provisions of this subpart.
[T.D. ATF-42, 42 FR 8373, Feb. 10, 1977]