Wash. Rev. Code § 63.14.060
Retail installment contracts negotiated and entered into by mail or telephone without solicitation in person by salespersons or other representatives of the seller and based upon a catalog of the seller, or other printed solicitation of business, if such catalog or other printed solicitation clearly sets forth the cash sale prices and other terms of sales to be made through such medium, may be made as provided in this section. The provisions of this chapter with respect to retail installment contracts shall be applicable to such sales, except that the retail installment contract, when completed by the buyer need not contain the items required by RCW 63.14.040.
When the contract is received from the retail buyer, the seller shall prepare a written memorandum containing all of the information required by RCW 63.14.040 to be included in a retail installment contract. In lieu of delivering a copy of the contract to the retail buyer as provided in RCW 63.14.030, the seller shall deliver to the buyer a copy of such memorandum prior to the due date of the first installment payable under the contract: PROVIDED, That if the catalog or other printed solicitation does not set forth all of the other terms of sales in addition to the cash sales prices, such memorandum shall be delivered to the buyer prior to or at the time of delivery of the goods or services.
RCW 63.14.060