- Fulfil and fulfill are both correct spellings of the same word. It means “to put into effect,” “to achieve,” “to carry out,” or “to realize.”
- Fulfil is the spelling commonly used in English speaking countries like the UK and Australia.
- Fulfill is the spelling commonly used in the United States.
- In Canada, they use both spellings.
Fulfill is one of those words with multiple spellings. It can end with two l’s or with one, depending on where the person writing the word is from.
Fulfil vs. Fulfill—What’s the Difference?
We use fulfill to say that we did something we promised, that we carried out a duty, or that we realized or put into effect something that someone entrusted us to do.
There are two ways you can spell the word—fulfill and fulfil. Neither of the spellings is wrong. The longer one, fulfill, is the spelling you’ll see people use in the United States:
In other English-speaking countries, people spell the word fulfil:
You can come across both spellings in Canada.
Most of the inflected forms of the word retain the double l, regardless of dialect. That’s why you’ll see fulfilling, fulfilled, and fulfiller in all English speaking countries. A notable exception is the word fulfillment, which follows the same rules as the root word:
Fulfill in the US
Fulfil outside of the US
American English and British English are different in many small, almost unnoticeable ways. When it comes to spelling, Americans usually prefer the shorter words, like “benefited” over “benefitted” or “check” over “cheque”, but every once in a while they choose to use the longer spelling, like fulfill.
from Grammarly Blog https://www.grammarly.com/blog/fulfil-vs-fulfill/