There is no legal requirement for a party to a marriage to change their name after the marriage ceremony. In addition, there is no one process or agency that will change or update your name for all agencies. To assume a new last name, you will need to contact each agency individually.
Agencies / organizations
Agencies or organizations you may consider changing or updating your name with may include social security, immigration services, the passport office, the state driver's license office, the county voter registration office, your employer, bank, or insurance company.
You may be asked to provide a certified copy of the Certificate of Marriage. Certified copies are available through the Snohomish County Auditor's Office Recording Division. For more information, please visit the Certified Copies of Marriage Records page.