Accounting standards recognise amortisation over a bond’s life, but tax authorities and administrative courts in Taiwan and the United States have long rejected deductions from interest income for bond premium amortisation. This study uses a comparative historical reconstruction of institutional interpretation to examine how institutions accepted or rejected accounting measurement ideas. In Taiwan, the legislative rationale of Article 62 of the Income Tax Act indicates a goal of aligning tax treatment with accounting standards. However, courts did not allow premium amortisation until the legislature in Taiwan inserted Article 24-1 of the Income Tax Act in 2007. In the United States, courts did not allow premium amortisation until Congress enacted Section 125 of Title 26 of the U.S. Code in 1942. Both Taiwan and the United States then maintained a non-retroactive approach.