WhatsApp quickly and easily recognizes which of your contacts are using WhatsApp by accessing your phone’s address book. Adding a new contact Save a contact’s name and phone number in your phone’s address book. If it’s a local number: Save the number in the same format you would use if you were to call that contact. If it’s a foreign number: Save the number in full international format: + [Country Code] [Full Phone Number]. Omit any leading 0’s from the phone number. Open WhatsApp and go to the Chats tab. Tap the new chat icon > Menu Button > Refresh.