I received CP12 and much of the issue stems from their claim of an incorrect social (which isn't correct) - what is the best way to resolve?

[Overtaxed2day]

They list 
- the Social Security number of one or more individuals claimed as a qualifying dependent was missing or incomplete.
- the last name of one or more individuals claimed as a qualifying dependent does not match our records
- one or more individuals claimed as a qualifying dependent exceeds the age limit
- the amount was computed incorrectly

One issue may stem from several years ago we DID enter a wrong social on the health care exchange.  But that was corrected.  I have one daughter below 16 and one over 18 and in college.

[VolvoGirl]

That sounds like this....

Those are just generic reasons why they adjusted the Recovery Rebate Credit on your return. A common adjustment is if you claimed the Recovery Rebate Credit on 1040 line 30 when you already got the 3rd Stimulus payment or reported the wrong amounts. Do you have an amount on line 30? The IRS knows they already sent it to you. Line 30 is only if you didn't get the full amount or qualify for more.

How much is missing? Check 1040 line 30. A common reason this year is if you tried to claim the Recovery Rebate Credit (for the 3rd Stimulus 1,400 per person) when the IRS already sent it to you. Line 30 is only if you didn't get the full amount or qualify for more. Not the amount you already got.

They sent the 3rd Stimulus payment (1400 per person) starting in March 2021. Double check your bank statements and check your IRS account (both accounts if married) to see what they sent you.
https://www.irs.gov/payments/your-online-account

[Overtaxed2day]

Thank you for your reply and the links. I did not receive that payment and I think that is the issue.  they are also stating AGI is too high (which is not and has not been.)

[VolvoGirl]

Yes those are the 5 reasons they give.  None are really the reason except the last one..,.. the amount was computed incorrectly.  After double checking your bank account and IRS accounts (both if married) then

If you didn't get the 3rd Stimulus check but the IRS shows they sent it to you then request a trace for a missing third Stimulus payment
https://www.irs.gov/newsroom/questions-and-answers-about-the-third-economic-impact-payment-topic-j-p...