Wash. Admin. Code § 308-96A-205
(3) What would the gross weight expiration date be when I increase the declared gross weight of my vehicle?
The new gross weight expiration date remains the same as the current gross weight license. You may choose to purchase additional months of gross weight not to exceed the vehicle registration expiration date.
(5) Will I receive credit for gross weight fees that I have already paid? Yes. You will receive dollar value credit for the number of months from the start date of the new gross weight license to the expiration of the current gross weight license. Credit is given for the gross weight that has already been purchased:
(6) How many months gross weight must I purchase when I increase the declared gross weight on my vehicle? You must purchase at least as many months as are remaining on the current gross weight license.
Credit will be given as provided in subsection (5) of this section. You will also be charged for the permit fees as defined in RCW 46.16.135, when applicable, in addition to all other fees required to license the vehicle.
[Statutory Authority: RCW 46.01.110, 46.16.070 and 46.16.135. WSR 02-11-095, § 308-96A-205, filed 5/20/02, effective 6/20/02; WSR 99-01-133, § 308-96A-205, filed 12/21/98, effective 1/21/99. Statutory Authority: RCW 43.17.060, 46.01.060, 46.16.070 and 46.16.135. WSR 92-02-100, § 308-96A-205, filed 1/2/92, effective 2/2/92. Statutory Authority: RCW 46.16.600, 46.16.276 and 46.01.110. WSR 87-12-023 (Order TL/RG-34), § 308-96A-205, filed 5/28/87. Statutory Authority: RCW 46.16.135, 46.16.225, 46.16.490 and 46.01.110. WSR 86-10-040 (Order TL/RG 24), § 308-96A-205, filed 5/5/86; Order MV-328, § 308-96A-205, filed 7/24/75.]