Form M1X: Amended Minnesota Income Tax

Form M1X is used to amend (correct) a previously filed Minnesota Individual Income Tax Return (Form M1). It allows you to make changes to your original tax filing and ensures your tax liability is accurate.

Who Should Use Form M1X?

  • Individuals who need to correct their originally filed Form M1, such as income mistakes, deductions, or credits.
  • Individuals who received a notice from the Minnesota Department of Revenue (MN Department of Revenue) indicating a change to their federal return that affects their Minnesota taxes.
  • Individuals who want to claim a refund due to an error on their original return.

What to Attach With Form M1X?

A. Completed Form M1X: Ensure you use the appropriate version for the tax year you're amending.

B. Corrected Schedules: Include any relevant schedules with the necessary corrections.

C. Copy of Form 1040X (if applicable): Attach a complete copy if you filed an amended federal return.

Key Points to Remember About Form M1X:

A. Filing Deadlines:

  • To claim a refund, file within 3 ½ years of the original due date for your return.
  • To avoid penalties, file within 3 ½ years of the original due date or the date you filed the return (whichever is later) if you owe additional tax.

B. Filing Method: Currently, Form M1X cannot be filed electronically. You must mail it to the Minnesota Department of Revenue.