Cancellation or cancelation? That is the question. Which do you prefer to use?
Always “cancellation”. American usage and British usage is the same for this word.
In American English, the verb ‘cancel’ is usually written as ‘canceled’ and ‘canceling’. However, in varieties of English from outside the United States, including Australian, British and Canadian English, ‘cancelled’ and ‘cancelling’ are the prferred spellings. Same goes with ‘cancellation’ and ‘cancelation’, I guess.