Limitations of WhatsApp Business API
Before you start using the WhatsApp Business API it is important to know the following limitations:
WhatsApp Business API restrictions
One of the things to keep in mind is the 24-hour limitation while using the WhatsApp Business API. This means that as soon as a customer sends a WhatsApp message to your WhatsApp Business Account (aka WABA) you are given 24 hours to respond to this message. This way a so-called 24-hour service-window is started. Within these 24 hours a normal conversation can be conducted in WhatsApp in which both parties can respond.
If you are not able to respond in 24 hours there are two alternatives which enable you to continue the conversation. You can either send a SMS or make use of WhatsApp Templates.
Starting a conversation initially is only possible with the use of WhatsApp templates on WhatsApp Business API.
Once a phone number is registered on the WhatsApp Business API, it cannot be used for WhatsApp Business or the WhatsApp consumer app. A phone number can be upgraded to the WhatsApp Business API, but never downgraded.
More information on the WhatsApp and Facebook policy around this matter can be found in the Facebook developers guide.
Currently WhatsApp group chat is not supported within the WhatsApp business API.
Calling through WhatsApp
Currently WhatsApp doesn't support calling through their WhatsApp Business API.