A method includes receiving a request for a list of nearby user devices, where the list of nearby user devices will be sent to a merchant device, where the merchant device is associated with a merchant, where the merchant operates a plurality of merchant devices, and where the merchant device is included in the plurality of merchant devices; receiving a respective location for one or more user devices, where each user device is associated with the merchant; determining, for each of the one or more user devices, whether the user device is nearby the merchant device, based on the respective location, to the merchant device than the other merchant devices in the plurality of merchant devices; generating the list of nearby user devices based at least on the determination; and sending the list of nearby user devices to the merchant device.