The correct American spelling for the past tense of the verb cancel is "canceled." However, the correct British spelling for this word is "cancelled" in other English-speaking countries, such as the United Kingdom, New Zealand and Australia.
The American and British spellings are different for certain English words, such as cancel, travel and grovel. In British spelling, the “l” is doubled if the word has a vowel before the”l.” The American spelling of these same words has the single “l.”
However, certain words like "extol" and "control" are spelled with the double “l” in both American and British usage when adding the endings "-ed" or "-ing" to them. The past tense of these verbs are "extolled" and "controlled."
There are many other spelling differences in American and British usages of words. For example, the American spelling of the word “color” is different than the British spelling given as “color.”