MW-3 Filing Deadline Extended to February 2, 2026

The Department of Revenue reminds employers that the deadline for submitting their 2025 Montana Annual Withholding Tax Reconciliation (Form MW-3) has been extended.

Because the legal due date of January 31 falls on a Saturday, reports received electronically or postmarked by February 2 will be considered as timely filed.

Here are some reminders to help avoid common mistakes that delay processing

• Ensure that the correct Federal Employer Identification Number (FEIN) and Montana Withholding account number (WTH) are shown on the MW-3
• Do not truncate information on the MW-3 or W-2s
• Provide updates to mailing addresses and other contact information

Please feel free to reach out to the Withholding Unit with any questions at (406) 444-6937 or MTDORWithholding@mt.gov.