Methods to Hack WhatsApp Account Using Phone Number Need physical access to the target phone Need a password/pin for that phone, if any WhatsApp Web issues a notification on Android that makes the owner alert if their WhatsApp is active on another device Open WhatsApp on your own device and enter the phone number of the target person On the prompt that appears, click OK to confirm the phone number The target device will receive a text message with the OTP As the OTP will be clearly visible to you, just enter it into your own device, and you’ll have access