mPOS
What Is mPOS? Definition and How It Works
Definition
mPOS (mobile point of sale) is a payment acceptance solution that uses a smartphone or tablet as the primary computing device, combined with a portable card reader attachment, to process card payments outside of a fixed checkout location. mPOS enables merchants to accept chip-and-PIN, contactless, and magnetic stripe payments wherever they operate, from market stalls to tableside restaurant service to mobile service businesses.
How it works
An mPOS system consists of two components: a mobile device (smartphone or tablet) running a payment application, and a card reader peripheral that connects to the device via Bluetooth, audio jack, or USB-C. The card reader handles the EMV chip reading, contactless NFC reception, and in the case of PIN-entry models, the encrypted PIN pad. The mobile application handles the merchant interface (product catalogue, transaction total, receipt generation) and communication with the payment processor.
When a customer pays, they insert, tap, or swipe their card on the reader peripheral. The reader encrypts the card data using point-to-point encryption (P2PE) and transmits it to the mobile application. The app sends an authorisation request to the payment processor over the mobile device's internet connection (4G, 5G, or WiFi). The processor routes the request through the card network to the issuer, which returns an approval or decline. The response is displayed on the device and the transaction is complete.
mPOS differs from SoftPOS (Tap on Phone) in that mPOS requires a separate hardware card reader peripheral: the smartphone alone cannot accept card payments without the reader. SoftPOS uses the device's built-in NFC chip, enabling contactless-only acceptance without any additional hardware. mPOS supports the full range of card acceptance including chip-and-PIN, which SoftPOS does not without additional PIN on glass certification.
mPOS solutions are offered by payment facilitators (Square, SumUp, Zettle by PayPal) who bundle hardware, software, and payment processing into a single integrated product. They can also be implemented by independent software vendors who integrate an mPOS SDK into an existing vertical software product and supply compatible card reader hardware to their merchant customers.
Why it matters
mPOS democratised card acceptance for small and micro-merchants who previously could not justify the cost and complexity of traditional fixed POS terminal installations. A food market vendor, a tradesperson, or a home services business can accept card payments with a reader that costs $20 to $100 and processes transactions through a mobile app with no monthly fees at low volumes. This removed a significant commerce friction point and contributed to the decline of cash in many markets.
For larger merchants, mPOS complements fixed POS infrastructure by enabling payment acceptance in overflow, outdoor, or mobile contexts. A restaurant adding outdoor seating during summer can equip servers with mPOS devices rather than running cable to new fixed terminals. A large retailer can deploy mPOS on staff devices to assist customers and take payments on the shop floor, reducing queue length at fixed checkpoints.
mPOS transactions qualify as card-present EMV transactions and receive card-present interchange rates, provided the card reader performs EMV chip authentication. This is a material cost advantage over card-not-present rates: for a merchant previously processing mobile sales as manual card-not-present transactions, migrating to mPOS can reduce interchange costs by 0.3 to 0.8 percentage points.
With PXP
PXP supports mobile card-present acceptance with fraud scoring, routing, and settlement in its in-store orchestration. Talk to our team about how PXP can support your mobile in-store acceptance.
Frequently asked questions
What is the difference between mPOS and SoftPOS?
mPOS requires a separate card reader hardware peripheral connected to a mobile device: the smartphone runs the payment app but cannot read cards without the external reader. SoftPOS uses only the mobile device's built-in NFC chip, requiring no external hardware, but is currently limited to contactless-only acceptance. mPOS supports the full card acceptance matrix including chip-and-PIN, chip-and-signature, magnetic stripe, and contactless; SoftPOS supports contactless card and digital wallet acceptance without a PIN pad unless using a PIN on Glass implementation.
How is mPOS card data secured?
mPOS security relies on point-to-point encryption (P2PE) in the card reader: card data is encrypted at the point of swipe, tap, or insert within the hardware reader, and remains encrypted until it reaches the payment processor's secure decryption environment. The mobile device never sees or stores unencrypted card data. mPOS implementations with a hardware reader are certified under PCI PTS (PIN Transaction Security, Point of Interaction) together with the PCI PIN and P2PE requirements, and undergo security assessments to certify the card reader and payment application. (Software-based PIN entry on a phone screen, used by SoftPOS, is governed instead by the PCI SPoC and MPoC standards.)
Can mPOS accept all card types?
A fully certified mPOS solution with an EMV-compliant chip-and-PIN reader accepts all major card types: chip-and-PIN credit and debit cards, contactless cards and digital wallets (Apple Pay, Google Pay) via NFC, and magnetic stripe cards on readers that include a mag-stripe slot. The specific card types supported depend on the card reader hardware's certifications. Contactless-only mPOS readers (lower cost, no PIN pad) support contactless transactions only, which has value limits and cannot process chip-only or magnetic stripe cards.
Revolutionize your business with PXP
Take complete control of your commerce and payments with one platform.
Get Started