Re: When a return is rejected for dependent social being on another return, let the preparer see who it is. - Intuit Accountants Community

R0000-507-01 - The First Dependent listed on your Tax Return was already Claimed as a Dependent.
R0000-507-02 - The Second Dependent listed on your Tax Return was already Claimed as a Dependent.
R0000-507-03 - The Third Dependent listed on your Tax Return was already Claimed as a Dependent.