# What does the VARTA error `provider_unavailable` mean?

Reserved as the fallback code for an unrecognised "provider unavailable" failure.


**HTTP status:** `503`  ·  **Type:** `provider_error`

## What it means

Reserved as the fallback code for an unrecognised "provider unavailable" failure.

## What causes it

Cause not yet documented as a live path under this exact code — it is the status fallback for a `/v1` handler that raises an unmapped 503 (`backend/app/api/v1/errors.py`). The one known 503 case today, no telephony provider configured, uses the more specific `telephony_not_configured` instead.

## What to do

Retry with backoff, or check whether `telephony_not_configured` is the more precise explanation.