Related Links and Forms
- Montana Withholding Tax Table and Guide
- Approved Withholding Tax Software Vendors
- Montana Wage Withholding Tax Reconciliation (Form MW-3)
- Montana Withholding Tax Payment Voucher (Form MW-1)
- Montana Employee Withholding Allowance and Exemption Certificate (Form MW-4)
- Business Tax Express
- Uniform Penalties and Interest
Due to changes to the federal Form W-4, the Montana Department of Revenue has implemented Montana Employee’s Withholding Allowance and Exemption Certificate (Form MW-4) for state purposes.
The Montana Department of Revenue will no longer accept the federal Form W-4. The federal Form W-4 should only be used for federal withholding allowance and exemption purposes.
For more information please review our Withholding Tax Guide
Who should complete a Form MW-4?
Your employee should complete Form MW-4 if they:
- Are a newly hired employee, or
- Claim to be exempted from Montana income tax withholding.
Your employee should consider completing a new Form MW-4 if their personal or financial situation changes.
They may be charged interest, penalties, or both when they file their individual income tax return if they do not have enough income tax withheld from their wages.
See Late Fees, Interest, and Penalties for more information on interest and penalties on underpaid estimated taxes.
Filing Form MW-4
You must file your employee’s Form MW-4 with the Department of Revenue only if one or both of the following applies:
- The employee is claiming more than 10 allowances, or
- The employee is claiming one of the withholding exemptions listed in Section 2 of the MW-4
If an employee provides you with a Form MW-4 that meets one or both of the conditions above, you must submit this form to the department by the last day of the payroll period in which the form was received.
File online using the department’s TransAction Portal (TAP).
For security reasons, employers must be logged into their TAP accounts to submit the Form MW-4.
Do not mail the Form MW-4 to the department.
You should keep a copy of all Forms MW-4 you receive from your employees with your records.