What This Letter Means
Letter 673C, Duplicate Returns Filed; Adjustment or Refund Explained, tells you the IRS found more than one return for the same tax year tied to your Social Security number. It fixed the duplicate and adjusted your account. The letter explains what it changed and what happened to any refund.
Common situations:
- Separate and joint returns. You filed as single, head of household, or married filing separately, and you also appear on a joint return. If the joint return is the valid one and it includes all the income, the IRS removes the separate return and moves any refund to the joint return.
- A return for each W-2 or 1099. The IRS combines the returns, adds up wages, other income, and withholding, and recomputes the tax.
- Returns under two different numbers. The IRS combines them under the correct number.
What to Do
- Compare the letter to your records. Check income, withholding, credits, and filing status.
- If the return the IRS kept needs changes, file Form 1040-X. The IRS will not make those changes on its own.
- In the future, put every W-2 and 1099 on one return. If a form arrives after you file, amend the return. Don't file a second one.
- If the adjustment created a balance due, pay it or set up a payment plan before it grows.
If You Didn't File One of the Returns
That points to possible identity theft. Call the number on your letter right away. You may need to file Form 14039, Identity Theft Affidavit.
Deadlines
This letter has no response deadline. If an amended return would get you a refund, it has to be filed within the normal time limits for refund claims.
If the IRS combined or removed one of your returns and the numbers don't look right, call us at (813) 229-7100.