Enforcement Rules for the Act Governing Relations between Peoples of the Taiwan Area and the Mainland Area Article 61

For a person of the Mainland Area who inherits the estate of a person of the Taiwan Area under Article 66 of the Act, Article 17 of the Estate and Gift Taxes Law regarding the deduction of tax payable shall apply mutatis mutandis to the filings of inheritance taxes.Any taxpayer applying for the additional itemization of tax deductions for heirs in the Mainland Area and the refund of excess tax payment shall proceed with the matter in accordance with Article 28 of the Law Governing the Levy of Tax.
中文原文 臺灣地區與大陸地區人民關係條例施行細則第61條
大陸地區人民依本條例第六十六條規定繼承臺灣地區人民之遺產,辦理遺產稅申報時,其扣除額適用遺產及贈與稅法第十七條規定。
納稅義務人申請補列大陸地區繼承人扣除額並退還溢繳之稅款者,應依稅捐稽徵法第二十八條規定辦理。

English translation for reference only; the Chinese text prevails. Not legal advice.