Mx51
Founded 2020 Β· 66 employees on LinkedIn Β· 7 known investors
mx51 provides a white-labelled, bank-grade Payment-as-a-Service platform that offers multi-channel payments and point-of-sale integrations for banks, merchant acquirers, and payment facilitators to serve their merchants. The company began in Australia and is expanding into new markets.
Also known as mx51 Β· MX51
Founders & leadership
Mx51 was founded in 2020 by Victor Zheng and Magnus Hsu.
Investors Β· 7
Also in the syndicate Β· 3
Company profile
researched Aug 2026mx51 is a Sydney-based payments technology company that supplies a white-labelled, bank-grade payments-as-a-service (PaaS) platform to banks, acquirers and other payment providers, which in turn serve their merchant customers. Its product set covers in-store payment terminal software ("Payment Flows"), a merchant dashboard offering near real-time reporting and analytics, a support dashboard giving payment providers fleet-wide operational insight, and business solutions such as disputes handling, reports and eStatements, and merchant insights.
The platform is designed to be device-agnostic across payment terminals and is complemented by point-of-sale integrations. mx51 publishes developer documentation for Simple Cloud Integration (SCI), a cloud-based API integration allowing a POS to initiate in-store transactions on an EFTPOS terminal without local software, using an SCI Pairing API (API secret key) and an SCI transaction API (HTTP Message Signatures, RFC 9421). It also documents an on-premise integration application, Spice, which third-party POS vendors such as LS Retail's LS Pay Engine integrate with over a local HTTP endpoint, supporting purchases, refunds, referenced and standalone refunds, last-transaction retrieval, and X/Z reports. Supported physical terminals documented include the Verifone VX690, e355, T650p, CM5 and CM5P, alongside a virtual test terminal called Gecko Bank.
In addition to technology, mx51 provides L1 and L2 merchant-facing support teams to reduce the support load carried by its payment provider clients.
Founding story
The business concept originated in 2016 as a slide in a presentation, according to co-founder and COO Magnus Hsu. mx51 was formed by spinning out of Assembly Payments in May 2020, where the founding trio had previously worked. It is led by CEO Victor Zheng, a former Westpac executive and former co-CEO of Assembly Payments. In 2021 the company formally appointed COO Magnus Hsu β a former quantum physicist who worked with Nobel Laureate William Moerner and later a Westpac executive β and Chief Product Officer Steven Hadley, previously a key figure in the launch of Commonwealth Bank's Albert terminal and creator of the prototype behind mx51's technology, as co-founders alongside Zheng.
Business model
mx51 sells its payments platform on a white-label basis to payment providers β banks, non-bank acquirers and payment facilitators β which deploy it under their own brands to merchants. Its offering combines platform software (terminal payment flows, merchant and support dashboards, analytics and dispute modules), a partner integration network for point-of-sale vendors, and outsourced level 1 and level 2 merchant support services.
Traction
By 2021 mx51 reported over $1 billion in transactions processed since founding, driven largely by its Westpac launch partnership, and stated a target of exceeding $10 billion in volume within the following 12 months. At the Series B in 2022 the company said it had doubled global headcount to more than 100 and was on track to more than double revenue that calendar year. Its website reports annualised transaction count and processed volume figures for 2025 and more than 100 partner integrations, and cites Commonwealth Bank and Westpac as customer references.
Latest developments
mx51's current site reports annualised 2025 transaction counts and processed volume, more than 100 partner integrations, and partnerships with Commonwealth Bank (CommBank Smart Sync and Smart Dash Portal) and Westpac. Its developer platform documents Simple Cloud Integration as a cloud-only POS integration path with RFC 9421 message-signature authentication, a certification process, and the Gecko Bank virtual test terminal as the recommended alternative to physical test hardware.
βΈFull profile β market position, technology, go-to-market, geography, history
Market position
mx51 positions its technology as enabling banks and acquirers to offer merchant payment experiences competitive with Stripe, Tyro and Square, allowing those institutions to retain the primary merchant relationship rather than cede it to independent providers. Investors have described the company as building bank-grade core infrastructure with comparatively little capital and as a candidate for global expansion from an Australian base.
Differentiators cited include a natively cloud-built, bank-grade platform used by major financial institutions, white-label delivery that leverages existing bank legacy infrastructure, a network of more than 100 global partner integrations for point-of-sale connectivity, multi-channel (in-store and online) coverage, and bundled level 1 and level 2 merchant support.
Technology
The platform is built natively in the cloud with an architecture the company describes as designed for scalability, availability and integrity. Terminal software is device-agnostic and supports Verifone classic and Android-based terminals. Integration options include Simple Cloud Integration, a fully cloud-based API with per-pairing base URLs, HTTP Message Signature authentication (RFC 9421), a polling loop for transaction updates, a dynamic "Action Framework" for rendering transaction UI, and mandatory transaction recovery/override flows; and Spice, a locally installed application exposing an HTTP API to POS systems. Feature coverage includes purchases, refunds, MOTO, surcharges, tipping, cashout, settlements, pre-authorisation, EFTPOS-based printing, pay at table and multi-pairing. mx51 maintains public code repositories including reference POS implementations in Swift, C# and Delphi, and internal CI/CD GitHub Actions.
Go-to-market
mx51 goes to market through partnerships with financial institutions that resell its technology under their own brands, using an initial launch partnership with Westpac as a reference deployment before extending to other Australian financial institutions, including Commonwealth Bank (CommBank Smart Sync and Smart Dash Portal). It maintains a POS partner program with dedicated relationship managers and public developer documentation, certification processes and test tooling to attract POS integrators.
Primary customers are banks, acquirers and payment providers; through them the platform reaches merchants ranging from SMEs to large enterprises. Named end-merchants on partner-deployed instances have included Lune Croissanterie, Pizza Hut, the Salvation Army and Carla Zampatti. Point-of-sale software vendors form a secondary partner audience via mx51's integration framework.
Geography
Headquartered in Sydney, Australia at Level 20, 135 King Street, NSW 2000. Operations began in the Australian market with major domestic banks as partners, and the company has stated intentions to expand internationally following its Series B, offering its solutions to payment providers globally.
History
mx51 spun out of Assembly Payments in May 2020 and launched with Westpac as its initial partner, processing over $1 billion in transactions within its first year. In 2020 it joined Mastercard's Start Path fintech accelerator. Less than 12 months after the spin-out it raised a $25 million Series A led by Acorn Capital, Artesian, Commencer Capital and Mastercard, and subsequently formalised Hsu and Hadley as co-founders. A $32.5 million Series B followed, led by an undisclosed global fintech investor with participation from Mastercard, Acorn Capital, Commencer Capital, Rampersand and Artesian, funding domestic scale and international expansion. The company has since added Commonwealth Bank as a partner, building CommBank Smart Sync and the Smart Dash Portal.
Compiled by commissioned research from 8 cited public sources β announcements, filings, and press listed under research sources below.
Key figures
latest reportedCompany-reported or press-reported figures, each dated to when it was claimed β not independently audited.
Timeline Β· 5
launches, deals, and filingsSeries B led by an undisclosed global fintech investor, with participation from existing investors Mastercard, Acorn Capital, Commencer Capital, Rampersand and Artesian. Funds allocated to local scale and international expansion, in-store and online payments, the merchant dashboard, fraud prevention and customer insights.
$32.5M source β
mx51 raised a $25 million Series A led by Acorn Capital, Artesian, Commencer Capital and Mastercard, its first major round, secured less than 12 months after spinning out of Assembly Payments. Proceeds were earmarked for Australian expansion, additional platform functionality and a 30% headcount increase.
$25M source β
mx51 appointed Chief Operating Officer Magnus Hsu and Chief Product Officer Steven Hadley as co-founders, joining CEO Victor Zheng. Hsu, a former quantum physicist and Westpac executive, led go-to-market strategy; Hadley, previously involved in the launch of CBA's Albert terminal, built the prototype underpinning mx51's technology.
mx51 was established as a separate business through a spin-out from Assembly Payments in May 2020, led by former Westpac executive and former Assembly Payments co-CEO Victor Zheng.
mx51 joined Mastercard's global fintech accelerator program Start Path in 2020.
Dated company events from announcements, filings, and press; legal rows summarize public dockets and regulator releases.
βΈResearch sources Β· 8
primary sources listed
- Mx51mx51.io Β· web
8 public sources were cited for this profile; the first-party ones are listed here.
Frequently asked questions
- What does Mx51 do?
- mx51 is an Australian payments-as-a-service company providing white-label, bank-grade payment platforms to banks and acquirers.
- Who founded Mx51?
- Mx51 was founded by Victor Zheng, Magnus Hsu in 2020.
- Who are Mx51's investors?
- Mx51's investors include Artesian, Cultivation Capital, Reinventure Group, SixThirty Ventures.