The Custom Challenge Prompt is a fraud-detection step that plays an audio challenge to callers Invoca’s fraud model suspects are automated (robocalls or bots), so genuine callers can pass through while suspicious calls are filtered out.
Prerequisites
This feature applies to accounts using Invoca’s Call Treatment Tree features, since the challenge prompt is configured as part of your call treatment setup.
How the challenge works
Once a call connects to Invoca, a fraud model analyzes audio cues to determine whether the caller is a human or an automated system. If a caller is flagged as suspicious, they hear a challenge prompt — by default, “Thank you for calling. Press N to continue,” where N is a number from 2 to 9, randomly generated for each call. You can customize this message, but any custom message must still include an instruction to press a key to continue; “Press 5 to continue” is the default keypress if you don’t specify your own.
Only callers the fraud model flags as suspicious hear this challenge. It lasts four seconds, and non-fraudulent callers hear normal ringing during this period, so most legitimate callers won’t notice any difference in their call experience.
What happens after the challenge
A caller who presses the requested key passes the challenge and connects directly through to Invoca as normal. A caller who fails to press a key, or whom the fraud model flags as fraudulent even after a keypress, is disconnected. This call is never reported in your Invoca platform or reports, and the time a call spends in the fraud detection system before connecting (or being disconnected) is never billed.
Testing the challenge prompt
To trigger a custom challenge prompt intentionally for testing, say a random verbal cue within the first few seconds of a test call — this may cause the fraud model to treat your test call as suspicious and play the challenge prompt, letting you verify your custom message and keypress behavior.Last modified on September 30, 2026
