Zoom Phone webhook delivery delays

Zoom API Event(s)

We subscribe to Zoom Phone webhook events such as phone.recording_completed and the other caller/callee call-log events.

Description

For our specific customer, webhook events intermittently stops entirely for about 30 minutes, and then all pending events are delivered in a burst within a few minutes, in chronological order.

Example

  • Call ended 2026-07-21 06:28:51 UTC, phone.recording_completed delivered 06:58:15 UTC (29.4 min delay)
  • Call ended 2026-07-21 06:29:54 UTC, phone.recording_completed delivered 06:58:22 UTC (28.5 min delay)

Over the past month, roughly 2,000 calls (~8% of this account’s calls) were affected.

Questions

  1. Is there per-account throttling, rate limiting, or back pressure on webhook delivery that a high-volume account can trigger? If so, what are the thresholds, and can they be raised for this account?
  2. What delivery latency should we expect for Zoom Phone webhooks (especially phone.recording_completed)? Is there a documented SLA/SLO for webhook delivery timing?
  3. Is there anything we (as the app developer) or the account admin can configure to prevent these stalls?
  4. If this behavior is by design, could you provide an official explanation we can share with our mutual customer?

The affected end customer is a major financial institution and the ~30-minute gaps are directly visible to their users, so we would appreciate your help in identifying the root cause.