TIN Validation Error AIRTN500 – Next Steps

*Note – This article is for Tax Year 2015. Guidance for Tax Year 2016 is located here:


One of the most common ACA e-filing errors returned from the IRS AIR system is the TIN Validation Error AIRTN500.

What causes TIN Validation Error AIRTN500?

This typically happens when the last name and SSN submitted in your filing doesn’t match what the IRS has on file. 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. The first last name listed in the last name field must be the one registered with the SSA.
  • A covered individual’s last name or SSN can cause this issue, and (unfortunately) the IRS does not tell us whether an employee or covered individual triggered the issue.
  • An employer EIN mismatch on the 1094-C in Part I and also in Part IV of the 1094-C for Aggregate ALEs. This can also cause TIN validation errors in the associated 1094-Cs for remaining ALE members.

How do I prevent this error going forward?

The best fix for TIN validation issues is to catch them before you submit your filings to the IRS. We strongly recommend verifying the TINs of all new employees and re-verifying existing employee’s TINs annually to catch any changes or updates.

If you are a BoomTax customer, you are entitled to receive 10 free verifications by registering with our affiliate TINCorrect:

TINCorrect – Employee and Vendor Verification Made Easy

How do I fix TIN Validation Error AIRTN500?

Depending on the issue, here are a few ways to correct a TIN validation error:

  • Verify the data you are filing matches a signed W9 or I9.
  • Contact your employees to get the correct information and document this thoroughly. According to the IRS:

Due to privacy/disclosure issues, we can only inform you that the name and social security number do not match our database. Ask your client to double check the information and if he still believes there is no error, have his employees contact IRS customer service who can direct them properly.  You or your client won’t be able to act on the taxpayer’s behalf without a proper POA so that is why we recommend that the employees in question call IRS to confirm what name and SSN is on file for them. The customer service number is 1-800-829-1040, or they can contact their local IRS office. There are also specific numbers per state on IRS.gov they can use if they wish.  Have them visit this  link – Local IRS Office Contact – for those numbers. There are no penalties for ‘good faith’ efforts.

  • Try alternate last names. Remember, only the first 4 letters of the last name are looked at for determining an IRS match, so if a last name like Smith-Wesson doesn’t match, you may want to try Wesson-Smith.
  • Remove the SSN for covered individuals on erred records, and use the date of birth instead. Since the IRS won’t tell you who triggered a TIN validation error on a form with covered individuals, the next best thing you can do is use the DOB for all covered individuals on erred employees. If there are still errors remaining after e-filing your corrections, then it must be on the employee record.
  • Request a TIN validation from BoomTax. As a courtesy to our clients, we offer an independent TIN validation for free as part of our service. Many times this will let you know if the error is triggered by a mismatch or if the SSN exists at all. If the SSN doesn’t exist, this could indicate a typo on the SSN number.
  • Correct your employer EIN or name (if the error happens on a 1094-C). You will also want to make sure to update the Part IV Aggregate ALE section in all affected filings as well.

I can’t fix this issue. What now?

In some cases, it won’t be possible to fix a TIN validation error. If an employee has left the employer and can’t be contacted, they may not be able to get an up-to-date TIN. In this case, the IRS has specified that you should follow (and document) the TIN solicitation process as follows:

  • Make an initial solicitation of recipient and covered individuals’ TINs at the time of enrollment unless you already have the required TINs.
  • If you do not receive the TINs, the first annual solicitation is generally required by December 31 of the year in which enrollment with the recipient begins (January 31 of the following year if the enrollment begins in December).
  • Generally, if TINs are still not provided, a second solicitation is required by December 31 of the following year.  If TINs are still not provided, no further solicitation is required.

BoomTax, The Boom Post, and its affiliates do not provide tax, legal or accounting advice. This material has been prepared for informational purposes only, and is not intended to provide, and should not be relied on for, tax, legal or accounting advice. You should consult your own tax, legal and accounting advisors prior to engaging in any transaction.

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2 thoughts on “TIN Validation Error AIRTN500 – Next Steps”

  1. My employer continues to receive this error when I have supplied them with all of the correct information. I even spent 2 hours on the phone with the Social Security Administration to check that mine and my daughter’s social security numbers are accurate. The employer does not seem to understand how to fix the problem and I do not want to be fined when I have full medical coverage. What do I do? Who should I contact?

    • You may want to forward this article to your employer so they’ll know the best way to follow up. You can also have them reach out to us if they have any questions or would like for us to look into their filing.

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