To determine which of your Dependents were already claimed, you will need to look at your full Reject Code.  The last two digits of the Reject Code tells you which Dependent it was based on the order they are listed on your Form 1040.

For example, Reject Code:

• 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