How do I proceed if Turbo Tax does not accept the zip code for my son's university that came directly from his Form 1098-T?

Google the correct zip code. If it really is correct, Look for a space or something that should not be there. If you still can't find the problem, follow these steps:

Desktop version: 

1. Delete the form 1098-T
2. Save your return while closing the program.
3. Update the program
4. Open
5. Enter the information again.

Online version:

A full or corrupted cache can cause problems in TurboTax, so sometimes you need to clear your cache (that is, remove these temporary files).

For stuck information follow these steps:

1. Delete the form 1098-T, see How to Delete  
2. Log out of your return and try one or more of the following:
   • Don't use Internet Explorer.
   • Clear cache and cookies,
   • Sign in using a different browser.
   • Sign in using a different device.
3. Log back into your return.
   • Enter the information again.