Washington payroll tax and registration guide

Updated October 27, 2023

This article will cover:

• What information OnPay needs from you
• What state and local taxes and filings OnPay handles for Washington employers
• Where you can find the tax account numbers needed
• Paying employees in other states?

Why is this important?

The following information requests and registration instructions are required before you can use a payroll provider to run payroll. This is in compliance with state payroll tax regulations. Without this information, OnPay is unable to file or deposit any tax payments for your company, and will not be responsible for any resulting penalties or interest. Note: If this isn't the only state where you have employees, there will be a separate guide like this one for each state where you hire and pay workers. 

Let Middesk handle your state tax registrations (and more)

If you'd like help, our partner Middesk makes hiring employees and staying compliant with every state agency simple and easy.

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

Learn more about Middesk→

What information OnPay needs from you

What state and local taxes and filings OnPay handles for Washington employers

Where you can find the tax account numbers needed

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

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

Unified Business Identifier (UBI)

Existing Washington Employer: 

You can find your UBI and Employment Security Account Number on the Quarterly Tax and Wage Detail Reports (Form EMS 5208 A). If you cannot locate this document or account number, please call the Washington Department of Employment Security at (855) 829-9243 (Persons with hearing or speaking impairments can call Washington Relay Service 711) to request it.

New Washington Employer: Register with the Washington Department of Employment Security

• Visit the Washington Department of Labor and click “Log in”.
• Look for a “New user? Sign up” link beneath the login fields.
• The online registration process can take up to 2 days. Once completed you will be notified of your tax deposit schedule.

ES (Employment Security) Account Number and Tax Rate

Existing Washington Employer: 

• You can find your ES Account Number on the annual Tax Rate Determination Notice received from the Washington Department of Employment Security. 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 in the lowest rate class pay 0.2%. Taxable employers in the highest rate class pay 6.00% (not including delinquency or Employment Administration Fund taxes). The wage base is $67,600. The experience “year” WA uses to calculate tax rates is July 1 - June 30.

New Washington Employer: Register with the Washington Department of Employment Security

• When you file for a business license application with the state of Washington, the Department of Employment Security will process your application and notify the WA Department of Labor & Industries to open a workers' compensation account and the ESD to open an unemployment insurance account.
• You'll receive a letter from your new Workers' Compensation account manager, and a packet of information which includes the following tax information:
  • Your Unified Business Identification (UBI)
  • Your ESD (Employment Security) Account Number (formerly known as ES Reference #)
  • Your Workers' Comp ( L&I ) Account ID
  • Your Participant Activation Code (PAC)
  • Your State Unemployment and Employment Administration Fund rate
• This will be sent to you 10 days after registering online, or in 21 days if registering by mail. Please email this information to hello@onpay.com.
• The new employer rate is a minimum of 1.00%, but is assigned based on average rates within an industry. The wage base is $67,600.

Employment Admin Fund Tax Rate

All Washington Employers: 

• Employment Admin Fund tax rates are assigned by the Employment Security Department. 
• If you are unsure of your rate, please call the agency at (360) 902-9670.

Labor & Industries Tax Rates

All Washington Employers: 

• These rates can differ per employee and are set based on the job the employee performs. The Department of L&I will assign the employer rates for each job type and the employer is responsible for keeping those rates updated in OnPay.
• The premium rates can change on an annual frequency, so it is very important to update those rates annually in OnPay. The rate for an employee changing jobs within a business needs to be updated as needed to ensure the employer is properly reporting their wages.
• Rates are set by the job type, but the Department of L&I gives employers the option to withhold some of the tax from the employees. OnPay allows an employer to update these rates within an OnPay account. 
• Rates must be added for any employee subject to L&I taxes or OnPay will not report for those employees. These rates can be updated in the Job section of each employee's individual profile. Rates entered incorrectly will accumulate and be paid with the rate it most closely coincides with.
• Information OnPay needs to file L&I: Employee premium rates, L&I account ID, & UBI number

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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