I (and the people I know) write resignation letters because it makes the intention clear (I really am resigning, not just sounding off because I'm annoyed or di

I (and the people I know) write resignation letters because it makes the intention clear (I really am resigning, not just sounding off because I'm annoyed or discussing possibilities). It also gets the facts down in writing in case of later possible confusion or dispute: in particular it ought to say "my notice period is X and I have Y days of leave outstanding, so my final day of work will be Z". Basically leaving work is a formal change in status that deserves to be memorialized in writing, just as the initial contract should be in writing and any subsequent changes would. That doesn't mean I wouldn't also talk to my manager, but the letter is important too I think.