This is the TIP FMM linkage....
Your TIP is only as good as long as your FMM is valid. You can show up at Aduana at the frontier and have a car permit with say 122 days remaining on it and an FMM that had expired a month earlier. The TIP AUTOMATICALLY has expired for a month. This was a huge issue in Chiapas a few years ago when INM FORCED extraneous to surrender their FMT when returning to Mexico from Guatemala and then issued the traveler a TRANSMIGRANTE 30-day permit. I went on some wild rides to INM with folks who did not believe the above. All I believe were very angry but they beat the deadline. One "caver" had to change off with his wife driving day and night.
The TIP is linked to your home country passport number and in no other way.
