Cal.com no_available_users_found_error
Quick answer
Seen when booking through the API or AI voice agents even though the UI shows slots. Check booking limits, required booking questions, and that timezone and time format are passed correctly.
Most likely fix: Match the booking questions
How to fix it
Try these in order — the most common fix is first.
1. Match the booking questions
- Open the event type > Advanced > Booking questions
- Make sure fields marked required are sent, or make them optional
Did this fix it?2. Check limits and the timezone
- Review booking frequency limits under Limits & buffers
- Send a valid ISO time and an explicit timezone
Did this fix it?3. Check status
- Check Cal.com's status page for incidents on the bookings endpoint (a 502 incident was logged in March 2026)
Did this fix it?
Symptoms
API v2 bookings return no_available_users_found_error or 502s while the UI works.
Why it happens
- Booking limits (daily/weekly/monthly) on the user or team
- Wrong time format or timezone in the payload
- Required booking questions (e.g. phone) missing from the request
- Temporary API outages
This guide also covers
- cal.com no_available_users_found_error
- cal.com api booking error
- cal.com retell booking
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