This was previously answered by Garry Lloyd Villaprudente who said: TidyCal’s group booking was updated so that when someone schedules a group session, each participant now needs to manually add the meeting via an "Add to Calendar" link in their email confirmation — this change prevents everyone from receiving updated calendar items each time someone else books. He also noted that TidyCal is not HIPAA compliant, so if you require HIPAA-level privacy for your health/wellness practice, TidyCal may not be the best fit and you should consider other HIPAA-compliant solutions. You can find that answer here: https://appsumo.com/products/tidycal/questions/i-love-this-app-for-11-booking-but-1173058/