Haw. Rev. Stat. § 236E-21
(a) If the amount paid with respect to any taxable transfer is less than the amount due under this chapter, the department shall assess the underpayment from the person responsible for payment, as follows:
(1) If a federal transfer tax return is due, a proceeding to assess the underpayment amount shall commence within:
(B) One year after the date of final determination of the related federal transfer tax,
whichever is later; or
(2) If a federal transfer tax return is not due, a proceeding to assess the underpayment amount shall commence within:
(B) One year after the date of final determination of the related Hawaii transfer tax,
whichever is later.
(c) If the amount paid with respect to any taxable transfer is more than the amount due under this chapter, the department shall refund the excess to the person entitled to the refund together with interest at the existing statutory rate of interest in the manner provided in section 231-23, as follows:
(1) If a federal transfer tax return was due, an application for refund shall be filed with the department within:
(B) One year after the date of final determination of the related federal transfer tax,
whichever is later; or
(2) If a federal transfer tax return was not due, an application for refund shall be filed with the department within:
(B) One year after the date of final determination of the related Hawaii transfer tax,
whichever is later.
[L 2012, c 220, pt of §1; am L 2013, c 60, §5; am L 2018, c 27, §13]
The 2018 amendment applies to decedents dying or taxable transfers occurring after December 31, 2017. L 2018, c 27, §15(2).