Hi there!

Our magstripe and chip card readers have the standard 3.5 mm headset plug and there aren’t variations in size.
 

Some phone cases are thicker and make it hard for the reader to fully connect with the headphone jack. You should hear a click when the reader is inserted into your mobile device, and a message should appear on your screen indicating the reader is connected.

Audio jack extenders or extension cables aren’t officially supported so we can’t guarantee compatibility, but some merchants have had success with them.

Another solution would be to switch over to the new version of our Square Reader. The Square Contactless and Chip Card Reader connects to compatible devices via bluetooth.