Washington Plumber Request for Change of Address is a document that must be filed with the Washington State Department of Licensing when a plumbing contractor wishes to change the address for their business. This document is required to keep records up-to-date and to ensure that the plumbing contractor is properly licensed in the state of Washington. There are two types of Washington Plumber Request for Change of Address: 1) Plumber to Change Business Address and 2) Plumber to Change Mailing Address. The Plumber to Change Business Address form is used when a plumbing contractor wishes to change the physical address of their business, while the Plumber to Change Mailing Address form is used when a plumbing contractor wishes to change the mailing address associated with their license. Both forms require the plumbing contractor to provide information such as the old address, new address, contact information, and license information. The forms must be signed by the plumbing contractor as well as a witness. Upon submission of the form, the Washington State Department of Licensing will review and process the request.