Haw. Rev. Stat. § 425-4: Partnership between husband and wife; prima facie proof.

If any business tax return is filed by, or license to do business is issued in the names of, both husband and wife, such tax return or license shall constitute prima facie proof, insofar as the State or any of its political subdivisions is concerned, that a partnership in such business exists between husband and wife in respect of such business. If the business tax return is filed by, or license is issued in the name of, one of them only, it shall constitute like proof that the husband and wife are not partners in respect of such business.