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If you are using a platform voice, fallback is handled automatically — no additional setup is required. The steps below only apply if you are using a custom or third-party provider voice.
When a TTS provider experiences an outage or temporary issue, your agent needs to keep talking. Fallback switches to a different voice provider seamlessly during the call.

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Default Fallback Behavior

If no custom TTS fallback is configured, UponAI uses a default fallback plan:
  • Uses a voice of the same gender as the original (if the original voice has a gender field)
  • Falls back to the next available voice in the fallback list in order
  • Once switched to a fallback voice, the agent stays on that voice for the rest of the call — even if the original provider recovers — to avoid jarring mid-call voice changes

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Setup a Custom Fallback Plan

Configure your own fallback plan so the replacement voice sounds as close as possible to the original.
1

Open Security & Fallback Settings

Go to your agent settings and open the Security & Fallback Settings panel.
2

Add fallback voices

Add one or more fallback voices. Each fallback voice must use a different TTS provider from the original voice and from each other.
3

Order your fallbacks

Arrange fallback voices in priority order. UponAI tries each in sequence if the previous provider is unavailable.
You cannot use the same TTS provider for both the primary voice and a fallback voice.