mx51 is a fintech that provides a white-labelled Payments-as-a-Service (PaaS) platform to merchant service providers such as merchant banks, payment service providers and acquirers.

Here’s a representation of the downstream value chain:

Clientception diagram

The product was born out of a project within Westpac (Project 51, later Carbon) in 2016. It was then handed to Assembly Payments for incubation in 2017 until it spun out into its own company mx51 (Merchant eXperience 51) in 2020.

A $25 million Series A round was completed in 2021, led by Acorn Capital, Artesian, Commencer Capital and Mastercard. Followed by a Series B raise of $32.5 million in 2022, less than 12 months after Series A. Series B was led by an undisclosed global fintech investor plus existing investors including Mastercard, Acorn Capital, Commencer Capital, Rampersand and Artesian.

The main focus of this Handbook is Product Technology. This is the technology that makes up the product that we sell as a service, for example, the software that we write that runs on our clients’ payment terminals, or microservices that we use to deliver the merchant dashboard.

Information about the products, features and capabilities can be found on our website mx51.io. References are made to terms we use at mx51 such as tenant, MXA and payment app, which are expanded on within sections of this handbook.

This handbook is used by internal staff and we’ve decided to make it public so you can see what we do.