Against what, the IRS checks your social security first when you efile?

[Pacun]

A client of mine went to another preparer and his efile was rejected because one of the family members had Obama Care and needed to reconcile. 

Preparer asked the client for the form from the exchange and client made calls and of course the exchange didn't have any forms to give him. Anyways, the preparer insisted and finally my ex-client called me in June. I said that my fees were 75% higher and that I was going on vacation. 

He patiently waited for my and two weeks ago, I worked on his return. I noticed the new preparer entered the wrong social security for one of his daughter and sure enough, my return was accepted flawlessly when I efiled. He received his 6K+ from the IRS and his 2K+ from MD.

So, the IRS gets a social security number and the first thing it does is to check it if he has an obama care flag. If flag exists, it reject the return. 

If flag doesn't exists, then it checks last name (and first initial), if they don't match, they reject it.

Does anyone know exactly the order of events when you enter a social security in an efile file? 

I believe the very first thing the IRS check is if that SS number has filed a return and then it check if that SS number has been claimed as a dependent.  Thank you.

[Randall]

I don't know the order but I had a client with custody of grandchild.  The mother/daughter was out there in never never land.  He has been claiming the child as a dependent.  But mother/daughter has been efiling early and claiming the child.  This past year, she must have claimed the market place credit so my client's return was accepted but IRS claimed back the advance credit from his refund.  He recently got it straightened out and received his full refund.  But the original IRS letter noted that a dependent ssn was the catch.  So yes, the ssn is checked somewhere along the line and matched up with everything else going on.