A mobile card reader is a small hardware device that connects to a tablet or smartphone to accept payment from debit or credit cards, essentially turning the device into a mobile point of sale (mPOS).
Mobile card readers offer various functions, enabling transactions through one or more methods including card swipe, chip card and contactless payment transactions. An associated mobile app usually provides common point-of-sale (POS) features such as receipts, invoicing, sales tax calculations, and so on. Typically, the devices are free or inexpensive and users are charged a small fee per transaction. Most are compatible with iOS and Android-based devices. Examples of mobile card readers include Square Reader, EMS+ and PayPal Here.
Mobile card readers and the associated technologies are one of the enabling elements behind the surging maker movement, a trend toward small-scale and wide-spread production. The ease and affordability these devices offer for card processing helps make small-scale production feasible.
See an introduction to installing and using the EMS+ mobile card reader: