Integration with Sunmi POS Terminals: Experience and Recommendations

on Jul30

The decline in cash payments across the globe has driven the rising demand for point-of-sale (POS) payment terminals. In particular, wireless devices such as tablets and smartphones capable of functioning as electronic POS terminals or cash registers are now highly sought after.
A great number of payment platforms and payment facilitators are looking for multifunctional ePOSs that would be a seamless match for their payment processing software while providing the best customer payment processing experience at any location.
The leading manufacturers in the payment processing terminals market are Verifone, Ingenico, and PAX. However, new manufacturers coming into the market can compete with these well-known vendors through implementation of innovative technologies.

Sunmi POS terminals

One of the daring newcomers is the China-based IoT company, Sunmi. In this article we decided to share United Thinkers experience of using their payment-enabled innovative solutions (Sunmi P2 Lite and P2 Pro), which far exceeded our expectations over this past year. Sunmi P2 Lite is a portable solution, which literally fits in your pocket and allows you to accept payments anywhere just by scanning the QR code. Sunmi P2 Pro is a universal portable POS, which, according to the company itself, “goes beyond finance”.
The Sunmi platform provided us with omnichannel payment capabilities, including contactless, chip & PIN, NFC, and QR code. Additionally, the model P2 Pro allows merchants to print receipts. Further, both devices can operate on 4G, 3G, Bluetooth, and WiFi networks.
Let us list the strong points of Sunmi solutions and the key aspects, which, based on our experience, can be further improved.

Sunmi POS terminals: praise and remarks


  • Sunmi POS terminals are designed as a top-notch hardware solution with flexible architecture. Their dust-and-water-proof cases are pleasant to touch and look at. The solutions are available in different formats: from smartphone and tablet to desktop and “kiosk” types. All modifications are equipped with handy full-touch screens and classical feature sets of smartphones – Sim card phone, WiFI, HD Camera, SD card. They do not need to be constantly “plugged in”, as they work on accumulator batteries. Additional equipment you can use in combination with the terminals includes EMV Card Reader, QR(Bar) Code Scanner, Receipt Printer.
  • POS terminals run on Android OS. They have their own app market (similar to Google Play), where you can place apps developed on Android. Approximately 10,000 portable and third-party applications, including office package, are available through the market. Existing mobile apps can be ported. This simplifies the servicing and minimizes the cost of solution development. To develop your own product, you can choose one of the two programming languages: Java and Kotlin. This provides wide opportunities for choosing open-source third-party libraries.
  • Sunmi’s own closed application market, ensuring flexible access rights for the app owner, allowing him to delegate rights to lower-level channel partners. It provides an opportunity to install apps on selected groups of terminals, based on serial number filtering. As a result, your app becomes less visible and exposed. Moreover, the opportunity to limit the series of apps allows you to simplify the choice for the merchant and make it more secure. The market restricts the source code access, enhancing protection against decompiling of your app’s code. App updates are automated.
  • Original Remote Assistant solution for remote control of the apps. You get a secure embedded solution for remotely controlling your apps in case of troubleshooting. Monitoring of terminals is also simplified, as no third-party solutions, such as TeamViewer, need to be installed. File system is easily accessible. Plus, you can always access the screen to remotely verify the working capacity of your solutions.
  • Available tech support from Sunmi development team. This tech support allows you to efficiently resolve the issues during EMV certification. You can always delegate development of some components (additional protocols and algorithms) to Sunmi team. If you have questions, as you study the solutions, Sunmi personnel is always there to provide answers.
  • Sunmi’s own multi-layered SDK, including their own security layer. Its main features and abilities include: crypto-key generation; injecting of specialized keys into a closed storage; several ways of PIN key injecting (USB, card, network); symmetric and asymmetric encryption; PKI (Public Key Infrastructure) support; embedded PIN Pad support; card data reading through EMV chip (contact/contactless) or magstripe; printing of receipts.
  • Availability of a demo version application providing source code. Sunmi developers add new example scenarios, once a new version of Sunmi SDK is released. Examples cover access to new hardware and EMV payment processing. Diagnostics of all available features of Sunmi terminals can be performed. The demo perfectly appends the somewhat limited reference documentation.

Potential for improvement

Of course, some aspects need to be added or improved in the process. For example:

  • The latest Android OS system version used in Sunmi POS terminals is 7.1.2.
  • Small-sized light indication of card status forced us to refrain from a series of tests during certifications using Visa payWave test tool.
  • We feel that support documentation is focused mainly on function syntax, while EMV error descriptions could be added to it. This inconvenience is somewhat compensated by availability of the demo version.
  • Some issues with the kernel were detected and fixed during the certification process.
  • Some encryption algorithms are missing. However, they are gradually being added to the logic.

As you can see, our remarks mostly concern documentation and encryption algorithms. However, Sunmi is a relatively new and developing brand. We recognize and relate to the difficulties the company has to take into account all at once. Especially, since they are creating innovative technologies. All issues are quickly resolved on Sunmi’s end and compensated for with their smart solutions, appended with a source code sample.


Designed with the latest innovations on the market in mind, the Sunmi models we are currently utilizing are a perfect match with our payment terminal solution module, UniRead. They enable us to provide businesses with a truly flexible payment terminal solution.
Feel free to contact our payment experts at to learn how UniPay technology in combination with Sunmi POS terminals can enhance the productivity of your business.

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