Hi ​@Stevec, our apologies for the headache this has caused. Unfortunately there, currently, is no admin setting in Calendly that allows you to turn off or reduce the Captcha requirement for invitees making bulk bookings. The Captcha challenge, ie. “I’m not a robot” grid, is triggered automatically when the system detects multiple bookings from the same IP address within a short period—typically after 2 or 3 bookings in an hour. This is a security measure to prevent automated spam and abuse.

Since this sounds like it is having a serious business impact, I’d recommend reaching out to support@calendly.com to see if they can elevate your issue.