26 C.F.R. § 50.8 Due date and place for filing returns and paying tax.
Title 26 - Internal Revenue
The return for a taxable year shall be filed with, and the tax shall be paid to, the district director at San Francisco, California, on or before September 30 of the calendar year in which the taxable year ends. The tax is due and payable on such date without assessment by, or notice from, the district director.
Title 26: Internal Revenue
PART 50—REGULATIONS RELATING TO THE TAX IMPOSED WITH RESPECT TO CERTAIN HYDRAULIC MINING
§ 50.8 Due date and place for filing returns and paying tax.