RCW 11.135.090: Witnessing.

(1) If other law of this state bases the validity of a nontestamentary estate planning document on whether it is signed, witnessed, or attested by another individual, the signature, witnessing, or attestation of that individual may be electronic.

(2) If other law of this state bases the validity of a nontestamentary estate planning document on whether it is signed, witnessed, or attested by another individual in the presence of the individual signing the document, the presence requirement is satisfied if the individuals are in each other's electronic presence, as defined in RCW 11.02.005.