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Last Updated: 12/18/2017

Filing an Amended Return

If you discover a mistake on a previously filed S Corporation Tax return, you must correct it by filing Form M8X, Amended S Corporation Return/Claim for Refund. Use the most current version of Form M8X, no matter what year return is being amended.

When to File

You may file an amended return within 3½ years of the due date or within 1 year of the date on a tax order (bill), whichever is later. If you filed your original return under an extension, you have 3½ years from the extended due date.

How to File

You must file Form M8X on paper. Enclose any additional lists of changes, amended schedules and a complete copy of your amended federal return (Form 1120S). Mail it to:

Minnesota Amended S Corporation Tax
Mail Station 1770
St. Paul, MN 55145-1770

Reporting Federal Tax Changes

If the IRS makes any change or correction to your federal income tax, you must report it to the Minnesota Department of Revenue within 180 days. Visit the Reporting Federal Tax Changes page for more information.