leaving Mexico for Belize
There is no fee for leaving Mexico , but if you are on a one-way trip and not planning to return to Mexico even during the vaildity period of your tourist card and import papers there are a few points to think of.
If at the start of your Mexico leg your credit card was refused ,(or had no card) for payment of the tourist tax you did have to post a bond, up to $400 depending on age of vehicle. You must now get your vehicle delisted from the Banjercito imported status so that you can collect back the bond money.
If you do plan to return, but at a time after your permits expire also get processed out and upon later return you can process in again and pay the fees anew.
If a planned return date falls within the period the permits and tourist card are valid , just get a stamp for exit in your passport but leave the tourist card and import papers alone, they will be accepted when you re-enter Mexico.At that time all you need to do is get another stamp in your passport.If you paid a bond to enter you will forfeit that money if you should fail to get back before the permits expire.
When entering Mexico from the USA DO NOT tell them it is only a transit to another country or you will be given a different set of rules and fees and a time limit to make the transit.
Belize does not charge anything to enter but there is a $20 tourist tax to EXIT.