Which type of device do you have?
The mobile card reader is compatible with all Apple devices running iOS 8 or higher. To find out which version is installed; Tap Settings> General> About> and look at the Version line.
If you're having trouble getting the reader to work try these Troubleshooting Steps.
The mobile card reader is compatible with most Android devices running OS version 4.0 or higher.
Because many different manufacturers make Android devices the hardware and software varies between each device. This makes it difficult to support the Mobile Card Reader on every Android phone or tablet. If you're having trouble getting the reader to work try these Troubleshooting Steps.
Currently we do not support the Mobile Card Reader or App on these mobile operating systems.
You can still process credit cards by keying in the card information or scanning the credit card.