traveling back to US from Mexico, checkin stating I need an application

[smlyon88]

I tried to check in for my return flight to US/California and it's saying I need an application. I have a passport (I am an American Citizen) and already used it going to Mexico.  I also cannot find an international phone number to call SWA to speak to someone.

[TheMiddleSeat]

Here's the number to call Southwest from Mexico

In Mexico
01-800-083-1179