[header] How to change your name in washington [title] Get a marriage license. [step] Once you marry, you have the right to change your name to your spouse's last name. You can also choose a hyphenated version of your name. 
[substeps] You can obtain a marriage license at your county auditor's office, most of the time. The state website has a list of most of the offices, so you can look up your county for more information.