https://devzone.nordicsemi.com/f/nordic-q-a/21515/how-to-read-0x1801-gerneric-attribute-service-in-iosHi, I have changed in my services so I have added 0x2A05 (service changed) characteristic in my 0x1801 service. But I am not able to read the service. In didDiscoverServices I have below code. - (void)peripheral:(CBPeripheral *)peripheral didDiscoverServicesen-USTelligent Community 13Fri, 21 Apr 2017 14:30:15 GMThttps://devzone.nordicsemi.com/thread/84459?ContentTypeID=1Fri, 21 Apr 2017 14:30:15 GMT137ad170-7792-4731-bb38-c0d22fbe4515:75233075-bb77-4549-9eab-efea9a7ecd74run_ar<p>If I remember correctly this characteristic is not exposed to the application on iOS. Instead this is handled by corebluetooth. Can you please check whether or not iOS enable this? Note that you need to bond for iOS to utilize this, and that you might have to toggle bluetooth off/on to flush the attribute cash on iOS, if you just added the characteristic.</p><div style="clear:both;"></div>