Huh? Are you preparing the 1040, or are you creating the W-2?

The issuer of the W-2 needs to add it to Box 1, not the preparer of the 1040. When we receive a W-2 from a client, we DON'T add that to Box 1. It should have already been added. If you are adding it when preparing the 1040, you are incorrectly adding income to your clients' tax returns.