Washington Payroll Tax – Knowledge Center

Which tax forms does OnPay file?

Unemployment: Form 5208A/B Washington Quarterly Tax and Wage Report

What information does OnPay need?

Washington Employment Security (ES) Reference Number Ex: 123456789
Washington Unified Business Identifier (UBI) Number: 9-digit number Ex: 000 000 000
Washington SUI Rate and 1-40 Employer Admin Fund Rate
Washington Labor & Industries (L&I) Account ID: 8-digit number Ex: 000-000-00

This information is required. If OnPay does not receive one or more pieces of the information listed above, we may be unable to file/pay one or more of your tax returns.

Where do I enter the information in OnPay?

Login to OnPay
Select the Settings menu icon
Select Payroll Tax
View/Update your Withholding Tax ID, Withholding Tax Deposit Schedule, Unemployment Tax ID, Unemployment Rate (as a %), and any local tax IDs as required.

Note: Washington assigns a Labor & Industries (L&I) rate for the employer and employee based the type of work the employee performs. These rates are entered on employee's profile under the Tax Setup section.

I am an existing Washington employer, where do I find the information?

If you are an employer with a history of payroll in Washington you have likely obtained the IDs and online accounts necessary for OnPay to process your tax filings.

Washington Department of Revenue:

Unemployment Account Numbers: Existing employers can find their UBI and ES Account Number on the Quarterly Tax and Wage Detail Reports (Form 5208 A).

The Department of Revenue processes your application and notify L&I to open a workers' compensation account and the Employment Security Department (ESD) to open an unemployment insurance account.

You should have received a letter from your new Workers' Comp account manager and a packet of information which includes the following tax information:

-Unified Business Identifier (UBI)

-ES (Employment Security) Account Number

-Workers' Comp Account ID

-Participant Activation Code (PAC)

-State Unemployment and Employment Administration Fund rate

Washington Department of Labor & Industries: (360)-902-4817

Unemployment Tax Rate: This can be found on the notice that you receive from the Washington Employment Security Department each year.

Additional helpful Phone numbers:

Washington Unemployment Insurance UI Web Tax: (800)-647-7706

Washington Industrial Insurance Quickfile: (360)-902-5999

Washington Employment Security Department: (855) 829-9243

I am a new employer, do I need to register for Washington Taxes?

Do you have a business and/or employees residing in the State of Washington?
Have you processed payroll in OnPay and have received warnings stating we are missing tax information?
Have you received an email from an OnPay Tax Agent requesting certain Washington information?

If you answered yes to any of the questions above, you should continue with the registration and setup steps below.

Which Washington Agencies should I register for?

Washington Employment Security Department: You will need to register with this department if you have employees that work in Washington. If your business is located out of the state, but some of your employee's primary work location is in Washington, you will need to register with this agency.

OnPay will use both the home address for each employee, plus the work site assigned to each employee to determine which taxes should be calculated.

Registration Information:

Washington Department of Revenue:

Click here to register your business with the Washington Department of Labor

The Department of Revenue processes your application and notifies L&I to open a workers' compensation account and the Employment Security Department (ESD) to open an unemployment insurance account.

You will then receive a letter from your new Workers' Comp account manager and a packet of information which includes the following tax information: