Haw. Rev. Stat. § 560:6-108: Financial institution protection; payment on signature of one party.

Financial institutions may enter into multiple-party accounts to the same extent that they may enter into single-party accounts. Subject to the provision of sections 236D-12 and 560:6-107, any multiple-party account may be paid, on request and according to its terms, to any one or more of the parties. A financial institution shall not be required to inquire as to the source of funds received for deposit to a multiple-party account, or to inquire as to the proposed application of any sum withdrawn from an account.