Whoever fails to pay any tax imposed by Part I of Subchapter A of Chapter 51 of the Internal Revenue Code (liquor taxes) or by Chapter 52 (tobacco taxes) at the time prescribed shall, in addition to any other penalty provided in the Internal Revenue Code, be liable to a penalty of 5 percent of the tax due but unpaid. For additional penalties for failure to pay tax, see 27 CFR 70.97 .
Assessable Penalties
27 C.F.R. §70.103
26 U.S.C. 5684(a) and 5761(b)