Haw. Rev. Stat. § 236E-11
If a federal transfer tax return is due and the date for filing the federal return or the date for payment of the federal transfer tax is extended by the Internal Revenue Service, the filing of the return and payment of the tax imposed by this chapter shall be due on the respective dates specified by the Internal Revenue Service in granting a request for extension. If the request for extension is granted by the Internal Revenue Service, the person required to file the Hawaii transfer tax return shall file along with the return required under this chapter a copy of the request for extension showing approval of the extension by the Internal Revenue Service. If a request for extension of time to file the federal return is denied by the Internal Revenue Service, no penalty shall be due under this chapter if the return required by this chapter is filed within the time specified by the Internal Revenue Service for filing the federal return. If a request for extension of time to pay the federal transfer tax is denied by the Internal Revenue Service, no penalty shall be due under this chapter if the tax is paid within the time specified by the Internal Revenue Service for paying the federal transfer tax. The extension shall be made by filing a true copy of the federal extension or extensions of time for filing or payment, or both, with the return required under section 236E-9.
If a federal transfer tax return is not due, the director of taxation may grant a reasonable extension of time for filing returns under rules as the department shall prescribe.
HRS § 236E-11