Section 9145 - Estate tax return(a) The person or persons required by section 2136 to make the inheritance tax return shall be initially liable for payment of the estate tax.(b) The personal representative of every decedent or, if there is no personal representative, any other fiduciary charged by law with the duty of filing a Federal estate tax return, within one month of the filing or receipt of the return shall file with the register or, if the decedent was a nonresident, with the register who issued letters, if any, in this Commonwealth, or otherwise with the department, a copy of the decedent's Federal estate tax return and of any communication from the Federal Government making any final change in the return or of the tax due. The assessment of estate tax shall be made by the register or department within three months after the filing of the documents required to be filed and, if not so made, shall be made within an additional period as the court, upon application of any party in interest, including the personal representative, shall fix.(c) The estate tax is due at the date of the decedent's death but shall not become delinquent until the expiration of nine months after decedent's death. Any estate tax occasioned by a final change in the Federal return or of the tax due shall not become delinquent until the expiration of one month after the person or persons liable to pay the tax have received final notice of the increase in the Federal estate tax.(d) No discount shall be allowed in paying the estate tax.(e) If the estate tax is not paid before the date it becomes delinquent under subsection (c), interest on the unpaid tax shall be charged after the date of delinquency at the rate established in section 2143 . (f) The estate tax shall be apportioned and ultimately borne in accordance with the provisions of 20 Pa.C.S. Ch. 37 (relating to apportionment of death taxes) unless otherwise provided by this article or in the instrument of transfer.(g) When the decedent was a resident, the estate tax shall be paid to the register. When the decedent was a nonresident, the estate tax shall be paid to the register who issued letters, if any, in this Commonwealth; otherwise, it shall be paid to the department.1971, March 4, P.L. 6, No. 2, Art. XXI, § 2145, added 1991, Aug. 4, P.L. 97, No. 22, § 36, effective in 60 days. Amended 2002, June 29, P.L. 559, No. 89, § 29, effective 7/1/2002; 2003, Dec. 23, P.L. 250, No. 46, § 26, imd. effective.