question

Hi, The ID is unique per install of the app, on a given device, for a specific user. If the user uninstalls then re-installs your app, you MAY receive a new registration ID. You can parse the response got after sending message to the specific device. when the request is successful. The response contains the canonical Registration ID for the specific instance of your app, which may be different that the one used for the request. At this point the data structure that stores the Registration ID values should be updated with the correct Registration ID for this particular app instance. String responseContent = parseResponse(conn.getInputStream()); System.out.println("responseContent -"+responseContent); JSONObject parsedObject = new JSONObject(responseContent); String canonicalRegistrationId = parsedObject .getString("registrationID"); // Check if the two Registration IDs are different. if (!canonicalRegistrationId.equals(registrationId)) { System.out.println(" UPDATE OLD DEVICE ID WITH NEW ID "); } This will keep it dynamic and not worry about the refresh rate.Hope this answers the issue.

Can we use the canonical Registration ID as the new registration ID? or the app instance needs to explicitly request a new one and send to our server?

canonical Registration ID is the new registration ID.