American Express Serve is primarily designed for use within the United States. However, it can be used internationally in locations where American Express is accepted, as long as the transaction is conducted in a supported currency. It is important to note that when using the Serve card outside of the United States, there may be foreign transaction fees associated with purchases. Additionally, some features, such as certain local services and reload options, may not be available outside the U.S. It is always a good idea to review the specific terms and conditions related to international usage and to stay informed about the fees that may apply. For detailed information, customers may want to check the official website, as it will provide the most current and relevant details regarding international transactions and usage limitations.