Error 507-01

[VidR]

I got error 507-01 when I try to efile my return. The same happened last year.  The error points to a dependent. ss# already used on another return.  Last year I called the SS office to verify the # and it is correct.  I ended mailing the return due to not being able to contact irs due to pandemic.  Can anyone advice?

[Just-Lisa-Now-]

that SSN has been used on a return already....you may want to request an IPPIN for your dependent so this wont happen in future years.

Form 15227