A modular device payment module includes a chassis. A modular device connector is located on the chassis. A payment module database in the chassis stores funding source information and security information. A payment module engine in the chassis determines that the modular device connector has been connected to a modular device frame of a modular device, and retrieves modular device identifying information from the modular device. The payment module then determines that the modular device identifying information matches an authorized modular device identified by the security information in the payment module database and, in response, enables the transmission of at least some of the funding source information from the payment module database to conduct a payment transaction.