Unique Identifier for Android Device

Question

I am looking for unique identifier for Android device. Which will be the best phone ID for that. IMEI creates problem in case of dual sim. I am registering it with first IMEI id, but when sim is changed to second slot it is returning second IMEI id.

What could be the best GUID for an Android device?

Answer 1

Google recommend to use advertising id You can find more info here: https://developers.google.com/android/reference/com/google/android/gms/ads/identifier/AdvertisingIdClient

Answer 2

There's new version of Google Play Services brings InstanceID, solution for uniuqe id:

Google Cloud Messaging and InstanceID

Previously, GCM used a unique registration ID to refer to each device - while these IDs will continue to work, you can now utilize Instance ID tokens for GCM, gaining all of the advantages of InstanceID around handling error cases. Instance ID tokens are fully compatible with user notifications, allowing you to send notifications to all of a user's devices.

http://android-developers.blogspot.com/2015/05/a-closer-look-at-google-play-services-75.html