Loud & Square

Q: I’m using a Square credit card reader that attaches to my smartphone, but I’m finding that the transactions don’t always go through properly. Is there a certain smartphone or cellular service provider that works better with these devices, or should I be using a different smartphone credit card reader?

A: The solution may be as simple as turning up the volume on your smartphone. The Square Reader (as with similar devices) draws its power from the smartphone’s audio port (standard 3.5mm headphone minijack), but if the smartphone’s volume is too low, the device may not be receiving enough power to work correctly or consistently.

Many smartphone-based credit card readers are on the market; each has different fees and capabilities. This industry is growing fast, and these devices’ plans and features are changing frequently. The brief comparison in this chart may help steer you toward the best option.