Wash. Rev. Code § 49.46.070
Every employer subject to any provision of this chapter or of any regulation issued under this chapter shall make, and keep in or about the premises wherein any employee is employed, a record of the name, address, and occupation of each of his or her employees, the rate of pay, and the amount paid each pay period to each such employee, the hours worked each day and each workweek by such employee, and such other information as the director shall prescribe by regulation as necessary or appropriate for the enforcement of the provisions of this chapter or of the regulations thereunder. Such records shall be open for inspection or transcription by the director or his or her authorized representative at any reasonable time. Every such employer shall furnish to the director or to his or her authorized representative on demand a sworn statement of such records and information upon forms prescribed or approved by the director.
RCW 49.46.070