However, notwithstanding paragraph (a)(4)(i) of this section, in the case of a termination assessment under section 6851, property seized may be sold after the due date (determined with extensions) of the taxpayer's return if the taxpayer does not file a return by such date. Furthermore, for the purposes of paragraph (a)(4)(ii) of this section, a petition will not operate as a further stay of the sale of the seized property unless the taxpayer files a bond as provided in section 7485.
26 C.F.R. §301.6863-2