The Washington State Department of Revenue has released interim guidance to help businesses prepare for changes related to Engrossed Substitute Senate Bill (ESSB) 5814, which takes effect on October 1, 2025. The new guidance provides clarification on how the updated retail sales tax will apply, including its impact on custom software.
This release marks the final installment in a series of Interim Guidance Statements developed to support taxpayers as they transition to the new rules. Businesses can rely on the interim materials until final or permanent guidance is issued.
The Department encourages retailers and other affected businesses to review the available resources, which include previously published guidance and frequently asked questions. Additional updates will be posted as implementation approaches.
For more information visit the Department of Revenue’s website
