The WhatsApp Business app is a free to download app for small businesses.

Before downloading the app, please be aware of the following:

• If you have an existing WhatsApp Messenger account, you can easily migrate your account information, including chat history and media, to a new WhatsApp Business account.
• Your chat history can't be moved back to WhatsApp Messenger if you decide to stop using the WhatsApp Business app.
• You can use both the WhatsApp Business app and WhatsApp Messenger simultaneously as long as the accounts are linked to different phone numbers. It's not possible to have one phone number linked to both apps at the same time.

Then:

1. Download the WhatsApp Business app from the App Store.
2. Verify your business phone number.
3. Restore from a backup, if you wish.
4. Set your business name.
5. Build your profile. Tap Settings > your business name.