I tried to amend one of my client’s 2024 tax returns from Married Filing Jointly to Married Filing Separately. However, the amendment was rejected by the IRS.

The rejection code IND‑451 states:

“An amended, superseded, or corrected return filed after the due date of the original return cannot have filing status ‘Married Filing Separately’ if the filing status of the original return was ‘Married Filing Jointly.’”

I went to the IRS website to investigate further and found that amending from MFJ to MFS is allowed under the following circumstances:

• The original 2024 MFJ return was timely filed (by April 15, 2025, or by the extended deadline if an extension was filed).

• Neither spouse has already filed a separate return for 2024.

• The amendment is within the three‑year window.

All of these conditions apply in my client’s case