Rules Of Grammar: Canceled vs. Cancelled vs. Cancellation
Geography seems to determine whether you use “canceled” or “cancelled.” According to Grammar Girl and Grammarist, “canceled” is the spelling that is favored by Americans. “Cancelled” is the spelling that is likely to be utilized in Britain, Canada, and Australia. Both grammar sources point out that the United States has only recently settled on the rule of using “canceled”; adopting the spelling as the favored method in the 1980s.
It should be noted, however, that “cancellation,” with two l’s, is the correct way to spell the word regardless of geographical region.