Save the contact’s phone number in your phone’s Contacts app
Make sure the number includes the correct country code
Open WhatsApp
Grant WhatsApp permission to access your contacts
Refresh your contact list in WhatsApp
On Android, tap New chat, then the menu, then Refresh
On iPhone, reopen WhatsApp or pull down on the Chats screen to refresh
Check that the contact is using WhatsApp
Make sure your phone’s contact sync is turned on
Update WhatsApp to the latest version
Restart your phone if the contact still does not appear