Here in this you are going to see how whataspp will work when given a other number in the verification process. (other number in the sense mobile which is not a smart phone)
For this,you need to have two mobiles (one is a smart phone and other is normal phone) with SIM inserted and with minimum balance.
And also the whatsapp need to be installed in mobile A(smart phone).
The following are the steps to verify:
1. Install the application in mobile A.
2. Launch the application.
3. Enter the mobile B mobile number and tap on “OK” button.
4. After 2 minutes,mobile B will receive a encrypted message from the mobile A mobile number.
5. Again after 5 minutes,mobile B will receive a message from Whatsapp server which contains 6 digits code.
6. After the total time(10 minutes),Displays a popup showing “SMS verification has failed,continue voice verification by calling the entered number”.
7. After tapping on “call me” button,again a popup appears with “Enter code here” field.
8. As soon as we tap on “call me” button, a call from Whatsapp server will come to the entered number.
9. This call will continue till we attend the call.
10. If the call was answered,a 6 digit number will be heard by voice.
11. If we enter the 6 digits code which was heard,The mobile A gets registered with the entered number and call gets automatically disconnected.
12. Otherwise if we enter the 6 digits code which was received as an SMS, the mobile A gets registered with the entered number.i,e. mobile B mobile number.
Here the mobile B will get the balance deduction,since mobile A has entered its number.
All the people in the mobile A whatsapp contacts list are able to see mobile B mobile number only.
So by this it is observed that whatsapp will consider only the IMEI of the application installed mobile and a valid number(even though it is not inserted in same mobile)
Understanding WhatsApp 