Military Members

Nonresident military personnel

Military personnel temporarily stationed in Washington are presumed to be nonresidents unless they were residents of Washington State when inducted.

Nonresident military personnel on duty in Washington may display any of the following: Washington license plates, plates issued from their official home of record, plates issued from a foreign (out of state) jurisdiction other than your official home of record, until the registration expires. For additional information review the Dept. of Licensing website.
http://www.dol.wa.gov/vehicleregistration/military-inwa.html

WA resident military personnel

If you’re a WA resident temporarily stationed in another state for military duty, you may continue to license your vehicles in Washington State. For additional information review the Dept. of Licensing website.
http://www.dol.wa.gov/vehicleregistration/military-outsidewa.html

Temporary Permits

You can get a temporary vehicle permit if you buy a vehicle while serving as a nonresident military personnel. The permit allows you to use the vehicle in Washington while you apply for out-of-state registration. The permit is valid for 45 days and must be displayed on the vehicle so it’s visible from the outside.
http://www.dol.wa.gov/vehicleregistration/militarypermits.html

Exemptions

Several types of tax exemptions may be available for Nonresidents stationed in Washington and Washington residents stationed outside the state.
http://www.dol.wa.gov/vehicleregistration/militaryexempt.html