The U.S. IRS has published two competent authority arrangements signed with the United Kingdom on 26 July 2021. The Competent Authority Arrangement Regarding United Kingdom Withdrawal from the EU concerns whether a person resident in the United Kingdom may continue to be considered a "resident of a Member State of the European Community" for the purposes of applying the so-called "derivative benefits test" in paragraph 3 of Article 23 (Limitation on benefits) of the 2001 US-UK Tax Treaty, including the term "equivalent beneficiary," as defined in subparagraph (d) of paragraph 7 of Article 23. The competent authorities agree that, for...