User interface handoff to enable feature at a terminal

An interface server comprising:

• a communications module;
• a processor coupled with the communications module;
• and
• a memory coupled to the processor and storing processor-executable instructions which, when executed by the processor, configure the interface server to:
• receive, by the interface server and from a point-of-sale terminal processing a transaction, a code request message including a terminal identifier identifying the point-of-sale terminal;
• generate, by the interface server, a machine-readable code encoding the terminal identifier as a parameter of a web address associated with the interface server, the web address for enabling completion of the transaction using a value-added service;
• transmit, by the interface server and to the point-of-sale terminal, a message including the generated machine-readable code and cause the point-of-sale terminal processing the transaction to display the generated machine-readable code, the machine-readable code encoding the web address to be used to request the interface server to enable completion of the transaction using the value-added service;
• receive, by the interface server and at the web address and from a device that scanned the machine-readable code, a message including the terminal identifier;
• in response to receiving the message from the device and at the web address, provide to the device an interface for obtaining input indicating customer data and consent to enable the value-added service;
• in response to receiving, by the interface server and from the device, a request including customer data based on input received through the interface, determine, based on the terminal identifier encoded in the web address, a list of unsupported merchants, data encoded in the machine-readable code and the customer data included in the request, that the transaction may be processed using the value-added service;
• and
• in response to determining that the transaction may be processed using the value-added service, enable completion of the transaction using the value-added service by sending, to the point-of-sale terminal caused to display the machine-readable code, an indication that the transaction is to be completed using the value-added service in order to cause the point-of-sale terminal to complete the transaction using the value-added service.