WA State Law
RCW 9.41.113
Firearm sales or transfers—Background checks—Requirements—Exceptions.
(1) All firearm sales or transfers, in whole or part in this state including without limitation a sale or transfer where either the purchaser or seller or transferee or transferor is in Washington, shall be subject to background checks unless specifically exempted by state or federal law. The background check requirement applies to all sales or transfers including, but not limited to, sales and transfers through a licensed dealer, at gun shows, online, and between unlicensed persons.
(2) No person shall sell or transfer a firearm unless:
(a) The person is a licensed dealer;
(b) The purchaser or transferee is a licensed dealer; or
(c) The requirements of subsection (3) of this section are met.
(3) Where neither party to a prospective firearms transaction is a licensed dealer, the parties to the transaction shall complete the sale or transfer through a licensed dealer as follows: