Montana payroll tax and registration guide

Why is this important?

To maintain compliance with state payroll tax regulations, you must provide the following information before you can use OnPay to run payroll:

State Employer Identification Number and state/local tax IDs
Tax rates - State tax offices set these rates based on the type, age, and size of your business
TPA and power of attorney - Most tax offices require this before we can submit quarterly wage reports and deposits on your behalf

This information must be provided and maintained by you in order for OnPay to accurately file and deposit tax payments for your company. OnPay is not responsible for any penalties or interest that incur due to missing or incorrect company tax information.

Each state has its own requirements, so if you pay employees in more than one state, you’ll find separate tax guides for each state.

Let Middesk handle your state tax registrations

Want help registering your business with state agencies? We've partnered with Middesk to make it simple for you to stay compliant in your state — and every state — when hiring employees.

Register with state agencies and get the tax IDs you need within minutes
Manage all your government accounts in one place using Middesk's intuitive platform
Stay compliant by managing agency mail and notices from your Middesk dashboard
Foreign Qualify with the Secretary of State to create payroll tax accounts

Learn more about Middesk

See what information you need to provide OnPay, and what taxes and filings OnPay handles for Montana Employers.

Information OnPay needs from you

Use this checklist to make sure you’ve covered everything required to set up your account as a Montana employer, so OnPay can accurately file and pay taxes on your behalf:

All Montana employers	What is this?
Make sure your business is registered with the Montana Department of Revenue	Allows your business to file and pay taxes in Montana More info >
Make sure your business is registered with the Montana Department of Labor & Industry	Allows your business to pay required unemployment insurance in Montana More info >
Provide OnPay with your Montana Tax ID and deposit schedule	The employer identification number issued by the Montana Department of Revenue More info >
Provide OnPay with your Montana Unemployment ID	A 6-digit number unique to your account with the Montana Department of Labor & Industry More info >
Provide OnPay with your Montana Unemployment (SUI) Rate	A tax rate you receive annually from the Montana Department of Labor & Industry More info >
Provide OnPay with your Montana Administrative Funding Tax Rate	A required fixed rate fee that supports the administrative of Montana’s UI Program More info >

Taxes and filings OnPay handles for Montana Employers

Withholding Tax

Form MW-1	Tax Payment Voucher	- Monthly, Quarterly
Form MW-3	Quarterly Withholding Return	- Quarterly
WT (Filing)	Employer’s Annual Transmittal of Montana Income Tax Withheld from Wages		- Annual
State W-2 (Filing)	Statement of Montana Income Tax Withheld and Wages Paid		- Annual

Unemployment Insurance Tax

Form UI-5

Quarterly Wage, Contribution and Employment and Training Assessment Report

- Quarterly

Other

New Hire Report (Filing)

Montana Report of New Hires

- As required

Where you can find the tax account numbers you need

If you are an existing employer who has previously run payroll in Montana, you likely already have the IDs and online accounts needed for OnPay to process your tax filings.

If you are a new employer in Montana, you will need to register your business with the Montana Department of Revenue and Montana Department of Labor & Industry. This must be completed for OnPay to be able to file and pay your Montana taxes.

Withholding Tax Account Number

Existing Montana Employer:

You can find your Withholding Tax Account Number on notices received from the Montana Office of Tax and Revenue. If you cannot locate this document or account number, please call the Montana Office of Tax and Revenue at (406) 444-6900 to request it.

New Montana Employer: Register with the Montana Department of Revenue

Business Federal Employer Identification Number (FEIN) or your Social Security Number (SSN)
If you do not have an FEIN for your business please visit IRS.gov to register for one
Secretary of State Identification Number (SOS ID)
Most businesses are required to register with the Montana Secretary of State. Please visit their website at sos.mt.gov to determine if you are required to register with them
The online registration process can take 1-2 days. Once completed you will be notified of your tax deposit schedule

Unemployment Account Number and Tax Rate

Updated January 1, 2025

Existing Montana Employer:

You can find your Unemployment Account Number on the annual Tax Rate Notice received from the Montana Department of Labor & Industry. It can also be found on your Quarterly Contribution and Wage Report)
Your Unemployment Tax Rate can also be found on the annual Tax Rate Notice in box 2
Employers generally have a rate ranging between 0% to 6.12% for SUTA with a wage base of $45,100

New Montana Employer: Register with the Montana Department of Labor & Industry

You can register your business with the Montana Department of Labor & Industry
You'll receive your account number and tax rate instantly once you have completed the online registration
New employers generally have a rate ranging between 1.3% to 2% for SUTA with a wage base of $45,100

Administrative Funding Tax Rate

All Montana Employers:

The Administrative Funding Tax Rate for Montana is typically 0.18%
Your rate can also be found on your annual Tax Rate Notice in box 3

Paying employees in other states?

If you operate in multiple states or just have employees working from home across a state line, it's important to file the correct state forms for those workers. See what forms we file in the states where you pay employees.

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