Haw. Rev. Stat. § 236E-13

If the amount of the federal taxable estate reported on an estate's federal estate tax return is changed or corrected by the Internal Revenue Service, the person required to make and file the estate tax return under this chapter shall provide notice of the change or correction to the department by filing, within ninety days after the final determination of the change or correction, or as otherwise required by the department, an amended return under this chapter, and shall furnish to the department any information, schedules, records, documents or papers relating to the change or correction. The time for filing the return may be extended by the department upon a showing of due cause. If an additional tax under this chapter is required to be paid pursuant to the changed or amended return, the person required to pay the tax shall pay the additional tax, together with interest as provided in section 236E-10, at the same time the supplemental or amended return is filed.