I just e-filed two tax returns of two different clients and they had the same rejection code - that the dependent has filed their own tax return.

[Reinafe]

One client checked the dependent's IRS transcript and it shows that no tax return has been e-filed.

The other client's dependent is a baby born in 2021.  

Could this be a glitch?

[IRonMaN]

Double check the Social Security numbers to make sure they are correct.  Was someone else potentially eligible to claim the kids on their returns?

[George4Tacks]

Carefully check that the SSN is correct and for the new child, that the name is spelled correctly. 

IRS online is slow to record returns. It is possible someone else filed with that taxpayer's SSN.