I've checked WikiDiff for the difference between expence and expense wanting to verify that it's corresponding to licence (the object or permission to do something) and license (the act of issuing said object or establishing/accreditation of said permission).
However, the explanation hit me with whoosh big time. I simply can't determine what's being said. I can't exclude error in the text, of course, but being humble I want to investigate if it might be me.
As nouns the difference between expense and expence is that expense is a spending or consuming often specifically an act of disbursing or spending funds while expence is.
Also, on top of that, it got me confused and uncertain about the actual difference so +1 to whoever answers that too.
Best Answer
"Expence" is an obsolete spelling of "expense" (like whiche and laste and many, many others) and should not be used. You might see "expence" in archaic documents, but in modern documents it's simply a spelling mistake.
Example from "The Expence of University Education Reduced: In a Letter to A. B. Fellow E.C." (1733)
Note the long s (ſ) which is pronounced like "s", as well as the capitalization of certain nouns, both of which no longer appear in modern English.