Will fly out on day 91 but check in is on day 90 so will have passed Thai immigration shall I give the officer the slip or report or do nothing?

Advice from old hands ,I'd like to get it right.

Can you do it early or shall Ijust post registerdto local office to cover poss flight delays.

Thanks in anticipASIAN

You can do 7 days early up to 7 days late so you should be safe whatever you do.

Thanks Lopburi for qwuickfire response!

your wise words always appreciated