One of the most common types of ACA e-filing errors returned from the IRS AIR system are TIN validation errors.
What causes a TIN Validation Error?
This will happen when the last name and SSN submitted in your filing doesn’t match what the IRS has on file, and this can happen for the following reasons:
- A maiden name was used when married name is registered with the SSA (or vice-versa)
- A Hispanic last name was used where 2 last names are common. In this case, the first last name listed in the last name field must be the one registered with the SSA.
- There is a typo in the last name or SSN field.
- An employer EIN mismatch on the 1094-C in Part I and also in Part IV of the 1094-C for Aggregate ALEs. (Note: This can also cause TIN validation errors in the associated 1094-Cs for remaining ALE members.)