How do I fix duplicate TIN errors during import?

The import message Duplicate TIN (SSN or EIN) found means more than one row in your upload has the same identifying details for that form type. It does not mean BoomTax has checked whether the TIN matches IRS records.

Review the rows reported in the import results

1. Compare the rows listed in the duplicate errors with your original spreadsheet.
2. If they are accidental repeats of the same intended form, remove the extra rows.
3. If a row has an incorrect TIN, correct it using your recipient records. Preserve leading zeros.
4. If the rows represent separate intended 1099-R forms for the same TIN, give each one a distinct Account Number.
5. Upload the corrected spreadsheet again and review the new import results.

Duplicate detection depends on the form type. For 1099-R forms, distinct Account Numbers can distinguish separate forms for the same recipient. Other form types may use different identifying details.

What about Allow Duplicates?

When importing into an existing filing, Advanced Import Options includes Allow Duplicates. This permits repeated records to pass the upload's duplicate check. Use it only when those repeated records are intentional.

Allow Duplicates does not guarantee that every row becomes a separate new form. The import mode and matching to forms already in the filing still affect the result. For separate intended 1099-R forms, use distinct Account Numbers rather than relying on this option.

If the error continues

Check the form type, tax year, Account Numbers and reported rows. Contact BoomTax support with the filing name, form type and error message if you need help identifying the match. Do not change a correct TIN or recipient name just to make the error disappear.

See How do I update many forms using an Excel spreadsheet? for the import modes and matching behavior.