Partnerships cannot choose a 53-week fiscal period
Unlike a corporation, which under s. 249.1(1)(a) is allowed to choose a 53-week fiscal period, under s. 249.1(1)(d) a partnership cannot have a fiscal period lasting more than 12 months. Thus, for example, if a partnership (with corporate partners which are not professional corporations) is formed on December 29, 2021, it must close off its first fiscal year on December 31, 2021 (in which case it could incur penalties under s. 162(7.1) if it forgets to file a return for that three-day year) – or, alternatively, its first fiscal period end could be at some later date partway through 2022, and it could apply to CRA for advance permission to change the second fiscal period end to December 31, 2022.
Neal Armstrong. Summary of Lorenzo Bonanno, “Problems with Fiscal Period of Partnerships and Subsection 249.1(1),” Canadian Tax Focus (Canadian Tax Foundation), Vol. 12, No. 1, February 2022, p. 4 under s. 249.1(1)(d).