It frequently comes to the attention of the CETIS-pedantry department that certain among the people with whom we interact, while they have much to say and write that is worth heeding, do not know when to use “licence” and when to use “license”. Those of you who prefer to use US English can stop reading now, unless you’re intrigued by the convolutions of the UK variant of the language: this won’t ever be an issue for you.
It’s quite simple: licence is a noun, it’s the thing; license is a verb, it’s what you do. But how to remember that? Well, hopefully you’ll see that advice is a noun but advise is a verb; similarly device (noun), devise (verb); practice (noun), practise (verb). Words ending –ise are normally verbs[*]. So license/licence sticks to the pattern of c for noun, s for verb.
Hope this helps.
[* OK, you may prefer –ize, which isn’t just for US usage in some cases–but that’s a different