Airline is rejecting my Green Card number
Hey all, I am planning a trip to Mexico for the first time since obtaining my green card and when I try to book the tickets online, it asks me for my Green Card number. In the infographic, it shows the back of the green card with 3 letters + the 10 numbers that follow it.
But when I type those in, I get an error message saying to enter between 9 and 10 characters, but if I remove the last digit, it accepts it. So I'm a little confused as to why it's asking for 9-10 characters but still accepts 12 and rejects 13. Any help is appreciated.