Yes, the American Express Serve card can be used for online purchases at various merchants that accept American Express. Since it operates as a prepaid debit card, it is important to ensure that there are sufficient funds loaded onto the card before making any purchases. When shopping online, users typically need to enter the card number, expiration date, security code, and billing address associated with the account during the checkout process. As a prepaid card, it may not have the same level of protection for certain online transactions as a traditional credit card, but it does provide a convenient way to shop online without needing a linked bank account. For more specific inquiries or details regarding usage policies or restrictions, individuals can refer to the relevant sections on the American Express Serve website.