How do I move my personal WhatsApp to the WhatsApp Business app and keep my chats?

Install WhatsApp Business on the same phone, accept its terms, choose your number and allow chat history and media to come across. Back up first, because moving back to Messenger is not supported.

• Back up first, to local storage or Google Drive. Then update WhatsApp Messenger and install WhatsApp Business.
• Accept the terms, choose your number and verify it with the SMS code. Then allow access to chat history and media.
• You can bring over media, chat preferences such as muted chats and ringtones, and chat history.
• Keep WhatsApp Business open and the phone on until the transfer finishes.
• One number cannot be on both apps. Using both on one phone needs a different number for each.