At the end of July, the United States and the European Union (EU) reached a provisional agreement to exempt aircraft and aircraft parts from U. S. tariffs. While the deal was announced in the summer, formal guidance was not issued until September 24, 2025. The published guidance confirms that imports of qualifying European aerospace products are now eligible for zero-tariff treatment, retroactive to September 1, 2025. This retroactive application is significant. Any entries made during September for EU-origin aircraft or parts where duties were paid should be reviewed. If duties were assessed at the time of entry, importers are advised to file amendments to recover those payments. Acting promptly will ensure full benefit from the duty-free treatment. It is important to note that this exemption applies only to EU-origin products. Aircraft and parts imported from Brazil remain subject to a 10% tariff, and those from Switzerland remain subject to a 39% tariff. Given the complexity of international aircraft transactions, consultation with a customs or trade advisor is strongly recommended before entering into any purchase or sale involving U.S. importation. This ensures that the parties fully understand the potential tariff exposure and clearly document which party will be responsible for import duties and compliance obligations.