Wash. Rev. Code § 82.23A.040
(2) Credit shall be allowed, in accordance with rules of the department, against the taxes imposed in this chapter for any petroleum product tax paid to another state with respect to the same petroleum product. The amount of the credit shall not exceed the tax liability arising under this chapter with respect to that petroleum product. For the purpose of this subsection:
(a) "Petroleum product tax" means a tax:
[ 1989 c 383 s 18.]