You may or may not have to remove your phone case – it depends on the material that the case is made from, how thick the case is, and how well your phone’s NFC antenna works. If your phone case is made from plastic or silicone or another non-conductive material, you will probably be able to scan the sensor without removing the case. If the case is aluminum, metal or anything else that has a conductive surface, you may need to remove the case before scanning your sensor. The thickness of the case can also make a difference. If your case is very thick, it could prevent the phone from scanning the sensor.