what I meant
@Ch***
is they don't stamp anything in your passport is. It's just a 90 day report receipt that has your next due date on it.
You can send your passport, a filled out TM47 form and your previous 90 day report form with who ever you want to.
Also remember you can file a 90 day report in person from 15 days before the due date until 7 days after the due date without any problem.