Washington payroll tax and registration guide

Use this checklist to make sure you’ve covered everything required to set up your account as a Washington 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 Washington, including:

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 0.20 percent. Taxable employers in the highest rate class pay 6.00 percent (not including delinquency or Employment Administration Fund taxes). The wage base is $62,500. 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 percent, but is assigned based on average rates within an industry. The wage base is $62,500.

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