RCW 43.216.528

The department shall adopt a rule that requires early childhood education and assistance program contractors and providers to accept birth certificates, passports, and alternative documents to show a child's age or date of birth for the purposes of enrollment. Alternative documents include, but are not limited to, a religious, hospital, or physician's certificate showing the date of birth, an entry in a family bible, an adoption record, an affidavit from a parent, or a previously verified school record.