Wisconsin Payroll Tax and Registration Guide

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

OnPay handles the filing of all state and local taxes for businesses in Wisconsin, including:

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

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

Withholding Tax Account Number

Existing Wisconsin Employer: 

You can find your Withholding Tax Account Number on notices received from the Wisconsin Department of Revenue. If you cannot locate this document or account number, please call the Wisconsin Department of Revenue at (608) 266-2776 to request it.

New Wisconsin Employer: Register with the Wisconsin Department of Revenue 

• Visit the One Stop Business portal and click “Start Your Business”.
• Complete their survey to determine the best way to register your business.
• You will be able to register for both Wisconsin Withholding and Unemployment Taxes

All Wisconsin Employers: Approve OnPay’s TPA access 

•  If your Business is already registered with the Wisconsin Department of Revenue, you will need to approve OnPay's pending request for 3rd party access. Once OnPay attempts to add your business, this request will be pending when you next log into your Wisconsin withholding account.
• If your Business has not yet registered with the WI Dept of Revenue, OnPay will need the Wisconsin Withholding Letter ID in order to add your business to our MyTax account.

Unemployment Account Number and Tax Rate

Existing Wisconsin Employer: 

• You can find your Unemployment ID on the annual Tax Rate Notice received from the Wisconsin Department of Labor. 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. Your rate will be in the range of 0% to 12% with a wage base of $14,000.
• Those in the construction industry or with an annual payroll over $500,000 should review this page to find their rate. 
• If you're unsure of your rate, please call the Department of Workforce Development at 1-(414)-438-5395.

New Wisconsin Employer: Register with the Wisconsin Department of Labor

• Visit the One Stop Business portal and click “Start Your Business”.
• Complete their survey to determine the best way to register your business.
• You will be able to register for both Wisconsin Withholding and Unemployment Taxes
• If you're a new employer in Wisconsin, your rate will generally be in the range of 3.05% to 3.25% with a wage base of $14,000.

All Wisconsin Employers: Provide OnPay with your Internet Access Code

• Log into your DWD account and choose the following from the home page:
  1. Account Access
  2. Generate Access Key
  3. Select All
  4. Click Generate Key
  5. The generated key will appear in Red at the top left
• If you don’t have an Internet Access Code, check any Wisconsin notices or letters you’ve received to see if you already have one. If you need to create one, or retrieve yours, contact the Wisconsin Department of Labor to request it.

OnPay works with government entities on your behalf, reporting new hires to state labor departments, calculating tax rates, and filing financial reports. To do this effectively, you will need to add OnPay Power of Attorney by following the instructions in this article.