The android.telephony.TelephonyManager class gives data about the communication administrations, for example, endorser id, sim serial number, telephone system sort and so forth. In addition, you can decide the telephone state and so forth.

activity_main.xml

<RelativeLayout xmlns:androclass="http://schemas.android.com/apk/res/android"  
    xmlns:tools="http://schemas.android.com/tools"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    android:paddingBottom="@dimen/activity_vertical_margin"  
    android:paddingLeft="@dimen/activity_horizontal_margin"  
    android:paddingRight="@dimen/activity_horizontal_margin"  
    android:paddingTop="@dimen/activity_vertical_margin"  
    tools:context=".MainActivity" >  
  
    <TextView  
        android:id="@+id/textView1"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_alignParentLeft="true"  
        android:layout_alignParentTop="true"  
        android:layout_marginLeft="38dp"  
        android:layout_marginTop="30dp"  
        android:text="Phone Details:" />  
  
</RelativeLayout>

Activity class

import android.os.Bundle;  
import android.app.Activity;  
import android.content.Context;  
import android.telephony.TelephonyManager;  
import android.view.Menu;  
import android.widget.TextView;  
  
public class MainActivity extends Activity {  
   TextView textView1;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
          
        textView1=(TextView)findViewById(R.id.textView1);  
         
        //Get the instance of TelephonyManager  
        TelephonyManager  tm=(TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);  
         
        //Calling the methods of TelephonyManager the returns the information  
        String IMEINumber=tm.getDeviceId();  
        String subscriberID=tm.getDeviceId();  
        String SIMSerialNumber=tm.getSimSerialNumber();  
        String networkCountryISO=tm.getNetworkCountryIso();  
        String SIMCountryISO=tm.getSimCountryIso();  
        String softwareVersion=tm.getDeviceSoftwareVersion();  
        String voiceMailNumber=tm.getVoiceMailNumber();  
          
        //Get the phone type  
        String strphoneType="";  
          
        int phoneType=tm.getPhoneType();  
  
        switch (phoneType)   
        {  
                case (TelephonyManager.PHONE_TYPE_CDMA):  
                           strphoneType="CDMA";  
                               break;  
                case (TelephonyManager.PHONE_TYPE_GSM):   
                           strphoneType="GSM";                
                               break;  
                case (TelephonyManager.PHONE_TYPE_NONE):  
                            strphoneType="NONE";                
                                break;  
         }  
          
        //getting information if phone is in roaming  
        boolean isRoaming=tm.isNetworkRoaming();  
          
        String info="Phone Details:\n";  
        info+="\n IMEI Number:"+IMEINumber;  
        info+="\n SubscriberID:"+subscriberID;  
        info+="\n Sim Serial Number:"+SIMSerialNumber;  
        info+="\n Network Country ISO:"+networkCountryISO;  
        info+="\n SIM Country ISO:"+SIMCountryISO;  
        info+="\n Software Version:"+softwareVersion;  
        info+="\n Voice Mail Number:"+voiceMailNumber;  
        info+="\n Phone Network Type:"+strphoneType;  
        info+="\n In Roaming? :"+isRoaming;  
          
        textView1.setText(info);//displaying the information in the textView  
    }  
  
     
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>  
<manifest xmlns:androclass="http://schemas.android.com/apk/res/android"  
    package="com.codebind.telephonymanager"  
    android:versionCode="1"  
    android:versionName="1.0" >  
  
    <uses-sdk  
        android:minSdkVersion="8"  
        android:targetSdkVersion="17" />  
  
    <uses-permission android:name="android.permission.READ_PHONE_STATE"/>   
      
    <application  
        android:allowBackup="true"  
        android:icon="@drawable/ic_launcher"  
        android:label="@string/app_name"  
        android:theme="@style/AppTheme" >  
        <activity  
            android:name="com.codebind.telephonymanager.MainActivity"  
            android:label="@string/app_name" >  
            <intent-filter>  
                <action android:name="android.intent.action.MAIN" />  
  
                <category android:name="android.intent.category.LAUNCHER" />  
            </intent-filter>  
        </activity>  
    </application>  
  
</manifest>