If you are late on a 90-day report, but you leave Thailand and return before you next visa-extension, will you still get a fine and a big red stamp in the passport about it?
TLDR : Answer Summary
If you are late on a 90-day report but leave Thailand and return before your next visa extension, opinions vary on whether you will incur a fine. Some commenters suggest that you might not face a penalty if the late reporting is not noticed during your next extension application. However, if you are inside Thailand when the report is due and miss it, you may expect a fine at the time of your next report, though it could be overlooked in some cases.