Some Apple users are having trouble with the Touch ID. Either the Touch ID feature did not work at all, or it gave problems recognizing the fingerprints or functioning as expected. While restarting the phone is a temporary fix for the problem, cleaning the sensor is all it took to solve the problem for a few other users. Other solutions that work are:
Solution 1: Update your Phone Software
Most of the times, the problem was solved by simply updating the phone software to iOS 10.2.1.
- Launch the Settings app from the Home Screen
- Tap on General
- Tap on Software Updates
If a new update is available then install it to your device.
Solution 2: Use multiple prints of the same finger
Some users who faced problems with Touch ID of recognizing the fingerprint found it easier to use multiple prints of the same finger. Scan the finger at different angles to help you solve the problem.