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 Near-Field Communication (NFC) antenna works. If your phone case is made from plastic, 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*.
* The FreeStyle LibreLink app and the FreeStyle Libre reader have similar but not identical features. A finger prick test using a blood glucose meter is required during times of rapidly changing glucose levels when interstitial fluid glucose levels may not accurately reflect blood glucose levels or if hypoglycemia or impending hypoglycemia is reported by the FreeStyle LibreLink app or when symptoms do not match the app readings. The FreeStyle Libre sensor communicates with the FreeStyle Libre reader that started it or the FreeStyle LibreLink app that started it. A sensor started by the FreeStyle Libre reader will also communicate with the FreeStyle LibreLink app. The FreeStyle LibreLink app is only compatible with certain mobile devices and operating systems. Please check the Compatibility Guide (PDF 69 kB) for more information about device compatibility before using the app. Use of FreeStyle LibreLink requires registration with LibreView.