Is there an exit tax leaving Mexico going to Belize

If you enter Mexico via air or sea and are using Mexico as a transition country to get to somewhere else, i.e. flying into Cancun and leaving to enter Belize, there is a fee.  DO NOT just "run the border"....first because you will have to check out of Mexico with your passport/visa.  The fee is legal.  The confusion arose because some who entered for less than 7 days and entered and left through the same MX border point were being charged the fee, which is not legal.  If you go from Belize to Chetumal for the day ( or any where for less than 7 days) and leave via the same border there is NO fee.  I'll try to find the corresponding Mexican regulation for this and post it later.

Hi,--- Thank you for the reply.
I phoned the Mex. Con. in Toronto they said no fee as we are not in Mex. more than 7 days and there is no such thing as double entry any more.
But I'm not sure if she fully understood me.
If you find any other info. it would be of a great help.

Thanks

The best advice is be prepared to pay.  If they don't require payment, count yourself lucky.  If they ask for payment, well, you were prepared to pay.  Have a great trip.

Hi -- I have been coming to Belize for 9 years now flying into Cancun and driving up to the border. For most of those years I paid the tax. Until 2 years ago when a custom guard told me I needed prof that the taxes had been paid by the airlines (Air Canada or West Jet)
So now I get a print out with my ticket number and a detailed copy of taxes paid by the air line which in turn I show to the Mexican tax dude at the border --so far that has worked 3 times with a no charge exit out of Mexico into Belize.---But like others say it depends on who is on duty

Anyway I hope this helps others

The short answer is if you arrive by air (or sea) and leave by land you owe the fee. If you arrive by land and leave by land AND stay more than 7 days you owe the fee.  Here is an update I posted elsewhere recently, hope it helps, -- So an update for all. I did the Cancun to Belize City on ADO night before last 11/20/2014. When you exit any of the three Cancun Airport terminals you will find someone at a small ADO kiosk near the buses to the right. You may purchase your ticket for the overnight to Belize here but must also buy a ticket to either Cancun or Playa del Carmen. Only Northbound buses (from BZ)stop at the airport. At this writing the fare to Cancun was $62 pesos, and the fare to Playa was $146 pesos. The fare Cancun to Belize City is $576 pesos and the fare Playa to Belize City is $534 pesos. So you can see it saves $42 pesos to backtrack to Cancun first not even counting the hassle and taxi expense of switching bus terminals in Playa. The bus doesn't leave till after 10 PM of course so if you arrive at the Cancun airport early in the day I would still advise spending the day in the much more pleasant Playa del Carmen. There are restaurants and other services in and near the Cancun ADO terminal. Oh, the man say it was $20 pesos less for an aisle seat so as this bus seems rarely full should save a couple $. As to the "exit fee". My ticket with US Airways showed only about $50 as fees with no breakdown. I inquired as to this at their customer service desk before I left Phoenix and they didn't know either. They researched a bit and printed a breakdown of fees but coded. Most were obvious airport charges (LAX, PHX etc.) with one for $21.50 USD for "UK". This code corresponds with the explanation from the Mexican Embassy in Belize here embamex.sre.gob.mx/belice/index.php/en/activities-a-notices/726 I circled this fee and later presented it to the Mexican Immigration officer at the Belize border who was demanding $25 USD. He said no problem, payment made. Save for a Belizean couple who had traveled to Cancun by bus everyone else aboard was forced to pay the $25US. So be sure to get a PRINTED and ITEMIZED receipt from your air carrier. One woman tried to show her receipt on her smartphone but the agent simply pointed to the sign that translates "No cell phone receipts".

The information Nate gave is detailed and correct .----Thank you so much for the work you put into it.--God be willing I will be driving through the border tomorrow.
Again thanks Nate.
Gary

We have also made the trip from Cancun...stopped in Playa for a couple days....bus on to Chetumal for a couple days, then took the water taxi to Ambergris.  We had no problems,  everything was checked at the water taxi and was very easy. 
We fly from Dallas,  and for app.$200 to Cancun, rather than $800 to Belize city, we find it well worth it.  If you have the extra time, enjoy Playa and Chetumal, all for less than one ticket to Belize City.