On December 1, 2021, the Tax Court issued a Memorandum Opinion in the case of Soni v. Commissioner (T.C. Memo. 2021-137). The primary issues presented in Soni were (1) whether the petitioners filed a valid joint return; (2) whether the period of limitations for assessment of tax under IRC § 6501(a) and (c)(4) expired before the issuance of the notice of deficiency; (3) whether the petitioners are liable for an addition to tax under IRC