KPMG report: Spain-United States implementing binding arbitration on tax treaty matters
Certainty in international tax disputes
Spain and the United States have finalized an arrangement implementing binding arbitration for tax treaty disputes, as provided under Article 26 of their bilateral income tax convention. The arrangement, signed by both countries’ Competent Authorities in late 2025, establishes the operational framework for arbitration within mutual agreement procedures (MAPs), assuring timely resolution of cases when double taxation or taxation not in accordance with the convention arises.
The new arrangement clarifies key aspects of the arbitration process, including panel composition, method of arbitration, role of the taxpayer, and the effective dates for arbitration eligibility.
Read a February 2026 report prepared by the KPMG member firms in the United States and Spain