What is the difference between license and licence? Are both variations accepted in US and UK?
In British English license is the verb and licence is the noun. American English uses license for both noun and verb.
The Corpus of Contemporary American English has 10263 incidences for license and just 91 for licence. The British National Corpus, in contrast, has 4217 for licence and 333 for license. Of those, 129 were for noun uses of license.
From this we can say that in the United States, the spelling license is nearly universal and licence is virtually unknown (with a ratio of more than 100 to 1 in favor of license). In Britain, the spelling licence is much more common than license, but the more common spelling is only about 13 times more common, so license is a small minority but not unknown spelling.
Update Oct 15, 2014:
Here we can see that British use of "license" reached a nadir in the 1950s, but has been on a steady upswing since the 1960s. According to this graph, in recent years use of "license" accounts for about 1/3 of uses of both spellings in Britain.