Reschedule and cancel bookings - Cal ID

Every booking has a unique id that you use to reschedule or cancel it. You can get this id from the response of Create a booking or by calling List bookings. Both endpoints require an API key sent as Authorization: Bearer calid_xxxxx.

Reschedule a booking

Send a PATCH request to /booking/\{id\}/reschedule with the new start time in ISO 8601 format. You can optionally include a reschedulingReason and the email of who rescheduled it (rescheduledBy).

curl -X PATCH https://api.cal.id/booking/{id}/reschedule \
  -H "Authorization: Bearer calid_xxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "start": "2026-05-03T11:00:00.000Z",
    "reschedulingReason": "Client requested a later slot"
  }'

{
  "success": true,
  "data": {
    "id": 123,
    "start": "2026-05-03T11:00:00.000Z"
  },
  "message": "Booking rescheduled successfully",
  "meta": {}
}

Cancel a booking

Send a POST request to /booking/\{id\}/cancel. Every field is optional. Include a cancellationReason, the email of who cancelled it (cancelledBy), and flags for recurring or paid bookings as needed.

curl -X POST https://api.cal.id/booking/{id}/cancel \
  -H "Authorization: Bearer calid_xxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "cancellationReason": "No longer needed"
  }'

{
  "success": true,
  "data": {
    "id": 123,
    "status": "cancelled"
  },
  "message": "Booking cancelled successfully",
  "meta": {}
}

Set autoRefund to true to refund paid bookings on cancellation. For a recurring series, set allRemainingBookings to true to cancel the rest of the series instead of just a single occurrence.

Related topics

Cancel a booking Allow Booking through Rescheduled Link Reschedule a booking Disable Rescheduling and Cancelling Allow Rescheduling Past Events

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