How many participants can I invite via WhatsApp?

In principle, you can add an unlimited number of participants to your event. There is no maximum number, not even if you send the invitation via WhatsApp. However, it may seem so: this is due to a restriction by WhatsApp itself (and unfortunately Cally cannot change this). 

Each time you want to share the invitation link, WhatsApp applies a maximum of five different chats. This restriction was put in place by WhatsApp to prevent spam from being sent around easily. If you want to send the invitation link to more than five different chats, you can simply check five chats each time, send the event link and then share again in this way.