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Posted 19 Feb 2013

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Detecting Incoming and Outgoing Phone Calls on Android

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13 Mar 2013CPOL3 min read
In this article, I'll show you how to detect incoming and outgoing phone calls on the Android platform.


In this article, I'll show you how to detect incoming and outgoing phone calls on the Android platform. It can be useful if you need to perform some action when a call is made. For example, to block it, to log it, or send call information to a server.

This article gives step-by-step instructions on how to create a simple demo app that will detect incoming and outgoing phone calls and show a "toast" message with phone number. You can extend and use this code for your own needs.

Incoming Calls

For incoming calls, we need to use the TelephonyManager class and its method listen to register a listener that will receive call state, data connection, network, SIM, and other events related to telephony. We are interested only in the call state notifications. This requires android.permission.READ_PHONE_STATE permission.

So, create our listener class derived from PhoneStateListener, and override the onCallStateChanged method, as follows:

* Listener to detect incoming calls. 
private class CallStateListener extends PhoneStateListener {
  public void onCallStateChanged(int state, String incomingNumber) {
      switch (state) {
          case TelephonyManager.CALL_STATE_RINGING:
          // called when someone is ringing to this phone
                  "Incoming: "+incomingNumber, 

Now I'll explain the onCallStateChanged method.

First argument - state is the call state, it can be CALL_STATE_RINGING, CALL_STATE_OFFHOOK, or CALL_STATE_IDLE. Ringing is the state when someone is calling us, offhook is when there is active or on hold call, and idle is when nobody is calling us and there is no active call. We are interested in the ringing state.

Second argument - incomingNumber, it's the number who is calling us.

As shown in the code above, the listener shows the "toast" message with the phone number when an incoming call is ringing.

Next, get an instance of TelephonyManager and register the listener:

tm = (TelephonyManager) ctx.getSystemService(Context.TELEPHONY_SERVICE);
tm.listen(callStateListener, PhoneStateListener.LISTEN_CALL_STATE);

When the app is no longer needed to receive notifications, it must unregister a listener by call:

tm.listen(callStateListener, PhoneStateListener.LISTEN_NONE);

Outgoing Calls

For outgoing calls, the system sends a broadcast action android.intent.action.NEW_OUTGOING_CALL. We need to make a broadcast receiver, that will receive the intent with this action.

To receive this broadcast, the android.permission.PROCESS_OUTGOING_CALLS permission is required.

Create the broadcast receiver class:

* Broadcast receiver to detect the outgoing calls.
public class OutgoingReceiver extends BroadcastReceiver {
     public OutgoingReceiver() {

     public void onReceive(Context context, Intent intent) {
         String number = intent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);
           "Outgoing: "+number, 

As with incoming calls, this code will show a "toast" message with phone number when there is an outgoing call.

Register the broadcast receiver:

IntentFilter intentFilter = new IntentFilter(Intent.ACTION_NEW_OUTGOING_CALL);
ctx.registerReceiver(outgoingReceiver, intentFilter);

We finished with the calls detection code. And now, we need to create an activity that will enable/disable calls detection. It will be an activity with a simple UI, with a textview showing detection status, button to enable/disable detection, and exit button.

But here is another issue - when our activity loses focus, calls detection is disabled. To prevent this, we have to make a service that will run and that will enable detection on start, and disable on stop.

Create the service:

 * Call detect service. 
 * This service is needed, because MainActivity can lost it's focus,
 * and calls will not be detected.
 * @author Moskvichev Andrey V.
public class CallDetectService extends Service {
    private CallHelper callHelper;
    public CallDetectService() {

    public int onStartCommand(Intent intent, int flags, int startId) {
        callHelper = new CallHelper(this);
        int res = super.onStartCommand(intent, flags, startId);
        return res;
    public void onDestroy() {

    public IBinder onBind(Intent intent) {
        // not supporting binding
        return null;

Create the activity.

Get the UI elements and set the onclick button handlers:

public void onCreate(Bundle savedInstanceState) {
    textViewDetectState = (TextView) findViewById(;
    buttonToggleDetect = (Button) findViewById(;
    buttonToggleDetect.setOnClickListener(new OnClickListener() {
         public void onClick(View v) {
    buttonExit = (Button) findViewById(;
    buttonExit.setOnClickListener(new OnClickListener() {
         public void onClick(View v) {

Create the setDetectEnabled method that will toggle calls detection:

private void setDetectEnabled(boolean enable) {
    detectEnabled = enable;
    Intent intent = new Intent(this, CallDetectService.class);
    if (enable) {
          // start detect service 
          buttonToggleDetect.setText("Turn off");
    else {
          // stop detect service
          buttonToggleDetect.setText("Turn on");
          textViewDetectState.setText("Not detecting");


<manifest xmlns:android=""
    android:versionName="1.0" >

        android:targetSdkVersion="15" />
         Permissions required for calls detection.
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS" />
        android:theme="@style/AppTheme" >
            android:label="@string/title_activity_main" >
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            android:exported="false" >



I showed you how to detect incoming and outgoing phone calls on Android. It is all quite simple. Please send me your comments and suggestions.

In the next articles, I'll show you other aspects of Android platform programming (networking, threads, multimedia processing, integration with websites and webservices, etc). You can download the latest version of the source code for this article here.


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Andrey Moskvichev
CEO BitGriff LLC
Russian Federation Russian Federation
My name is Andrey Moskvichev.

I'm a software developer with more than 14 years of programming experience.

I specialize in networking, Unix systems (Linux, FreeBSD), mobile programming, computer graphics, software architecture, reverse engineering, data processing systems, AI, computer vision.

I'm interested in all new cutting edge technologies.

Comments and Discussions

QuestionIncoming Call not detected for device API>=26 whenever app is closed and not running even in foreground Pin
Member 1386893813-Jun-18 2:19
MemberMember 1386893813-Jun-18 2:19 
QuestionGreat Pin
Harvey Green12-Apr-17 22:31
MemberHarvey Green12-Apr-17 22:31 
QuestionAfter removing app from recent apps means clearing memory i am not able to detect call Pin
Kishan Gohel2-Jan-17 2:33
professionalKishan Gohel2-Jan-17 2:33 
Questionthanks you sir you save my lot of time. Pin
Member 1277795515-Nov-16 0:17
MemberMember 1277795515-Nov-16 0:17 
Suggestiondetecting incoming and outgoing calls Pin
AustinHoffman5-Sep-16 3:56
MemberAustinHoffman5-Sep-16 3:56 
QuestionSIP Calls Pin
Member 124341333-Apr-16 14:11
MemberMember 124341333-Apr-16 14:11 
Questionautomatic conversion from slient mode to ringing mode Pin
Member 1234989224-Feb-16 15:04
MemberMember 1234989224-Feb-16 15:04 
QuestionHow do you detect the SIM details Pin
Member 123029532-Feb-16 5:33
MemberMember 123029532-Feb-16 5:33 
Questioncan we send the digits to the incoming number Pin
prakashrao26-Dec-15 0:03
Memberprakashrao26-Dec-15 0:03 
QuestionHow to detect the end of an outgoing call? Pin
Dismi12-Jan-15 1:16
MemberDismi12-Jan-15 1:16 
QuestionGet a Web page title when incoming or outgoming calls Pin
Panos Marmaras3-Jan-15 8:22
MemberPanos Marmaras3-Jan-15 8:22 
QuestionMy vote 5 Pin
WuRunZhe2-Sep-14 17:16
MemberWuRunZhe2-Sep-14 17:16 
QuestionMy application crashing when using your code with a small addition of "writing to file" Pin
Member 1095618718-Jul-14 8:16
MemberMember 1095618718-Jul-14 8:16 
AnswerRe: My application crashing when using your code with a small addition of "writing to file" Pin
Member 1095618718-Jul-14 10:00
MemberMember 1095618718-Jul-14 10:00 
QuestionMultiple callbacks to onCallStateChanged() Pin
SLCompulsion26-Jun-14 7:44
MemberSLCompulsion26-Jun-14 7:44 
QuestionDetect ringing state at outgoing call Pin
HichemSeeSharp25-Jun-14 11:10
MemberHichemSeeSharp25-Jun-14 11:10 
GeneralMy vote of 5 Pin
Scyalsdk13-Jun-14 5:50
MemberScyalsdk13-Jun-14 5:50 
QuestionAndroid Project Control incoming messages from certain numbers Pin
makhondi28-Oct-13 6:46
Membermakhondi28-Oct-13 6:46 
AnswerRe: Android Project Control incoming messages from certain numbers Pin
Andrey Moskvichev30-Oct-13 21:32
professionalAndrey Moskvichev30-Oct-13 21:32 
Questioncorrection of code Pin
Isha Gupta1-Aug-13 0:59
MemberIsha Gupta1-Aug-13 0:59 
AnswerRe: correction of code Pin
Andrey Moskvichev30-Oct-13 21:31
professionalAndrey Moskvichev30-Oct-13 21:31 
QuestionSome confusing Pin
duong217914-Jun-13 18:13
Memberduong217914-Jun-13 18:13 
AnswerRe: Some confusing Pin
Andrey Moskvichev22-Jun-13 0:08
professionalAndrey Moskvichev22-Jun-13 0:08 
Questionwhy incomming call detection dosen't use ctx.registerReceiver Pin
tieubuidoi12312-Jun-13 17:54
Membertieubuidoi12312-Jun-13 17:54 
Questionwhy incomming call detection dosen't use ctx.registerReceiver Pin
tieubuidoi12312-Jun-13 17:54
Membertieubuidoi12312-Jun-13 17:54 

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