Wash. Rev. Code § 67.70.200
The director, in his or her discretion, may require any or all lottery sales agents to deposit to the credit of the state lottery account in banks designated by the state treasurer, all moneys received by such agents from the sale of lottery tickets or shares, less the amount, if any, retained as compensation for the sale of the tickets or shares, and to file with the director or his or her designated agents, reports of their receipts and transactions in the sale of lottery tickets in such form and containing such information as he or she may require. The director may make such arrangements for any person, including a bank, to perform such functions, activities, or services in connection with the operation of the lottery as he or she may deem advisable pursuant to this chapter and the rules of the commission, and such functions, activities, or services shall constitute lawful functions, activities, and services of such person.
RCW 67.70.200