An electronic payments platform operates by hosting a payments server (100) accessible via the internet (200) and storing a record of payment transactions made via merchant devices (300) comprising merchant smartphones.

Merchant devices (300) download and install as a transaction app (830) supported by an authentication service (840) in communication with each other when installed in the merchant device, and also with a payments server (100). The transaction app (830) requests purchases initiated using a customer card or device (300) at the merchant device (300)