If you failed to enter the IP PIN before you filed then expect the return to reject  ... then you can fix your error and file again. 

If you have a 6-digit IP PIN to enter, here's where to enter it.

·         FEDERAL TAXES tab. (or Personal tab in Home and Business)

·         Then sub tab "Other Tax Situations."

·         Scroll down to "Other Return Info".

·         Find subtopic "Identity Protection PIN", and click START.