Washington Revised Code Title 48. Insurance § 48.80.040. Use of circumstantial evidence

(1) Where a claim for a health care payment is submitted with the person's actual, facsimile, stamped, typewritten, or similar signature on the form required for the making of a claim for health care payment; and

(2) Where a claim for a health care payment is submitted by means of computer billing tapes or other electronic means if the person has advised the health care payer in writing that claims for health care payment will be submitted by use of computer billing tapes or other electronic means.