diff --git a/nanobot/channels/base.py b/nanobot/channels/base.py
index dd29c0851..27d0b07a8 100644
--- a/nanobot/channels/base.py
+++ b/nanobot/channels/base.py
@@ -24,6 +24,7 @@ class BaseChannel(ABC):
     display_name: str = "Base"
     transcription_provider: str = "groq"
     transcription_api_key: str = ""
+    _transcription_fallback_key: str = ""
 
     def __init__(self, config: Any, bus: MessageBus):
         """
@@ -38,19 +39,30 @@ class BaseChannel(ABC):
         self._running = False
 
     async def transcribe_audio(self, file_path: str | Path) -> str:
-        """Transcribe an audio file via Whisper (OpenAI or Groq). Returns empty string on failure."""
+        """Transcribe an audio file via Whisper. Falls back to the other provider on failure."""
         if not self.transcription_api_key:
             return ""
+        result = await self._try_transcribe(self.transcription_provider, self.transcription_api_key, file_path)
+        if result:
+            return result
+        fallback = "groq" if self.transcription_provider == "openai" else "openai"
+        if self._transcription_fallback_key:
+            logger.info("{}: trying {} fallback for transcription", self.name, fallback)
+            return await self._try_transcribe(fallback, self._transcription_fallback_key, file_path)
+        return ""
+
+    async def _try_transcribe(self, provider: str, api_key: str, file_path: str | Path) -> str:
+        """Attempt transcription with a single provider. Returns empty string on failure."""
         try:
-            if self.transcription_provider == "openai":
+            if provider == "openai":
                 from nanobot.providers.transcription import OpenAITranscriptionProvider
-                provider = OpenAITranscriptionProvider(api_key=self.transcription_api_key)
+                p = OpenAITranscriptionProvider(api_key=api_key)
             else:
                 from nanobot.providers.transcription import GroqTranscriptionProvider
-                provider = GroqTranscriptionProvider(api_key=self.transcription_api_key)
-            return await provider.transcribe(file_path)
+                p = GroqTranscriptionProvider(api_key=api_key)
+            return await p.transcribe(file_path)
         except Exception as e:
-            logger.warning("{}: audio transcription failed: {}", self.name, e)
+            logger.warning("{}: {} transcription failed: {}", self.name, provider, e)
             return ""
 
     async def login(self, force: bool = False) -> bool:
diff --git a/nanobot/channels/manager.py b/nanobot/channels/manager.py
index b52c38ca3..d7bb4ef2d 100644
--- a/nanobot/channels/manager.py
+++ b/nanobot/channels/manager.py
@@ -41,6 +41,8 @@ class ChannelManager:
 
         transcription_provider = self.config.channels.transcription_provider
         transcription_key = self._resolve_transcription_key(transcription_provider)
+        fallback_provider = "groq" if transcription_provider == "openai" else "openai"
+        fallback_key = self._resolve_transcription_key(fallback_provider)
 
         for name, cls in discover_all().items():
             section = getattr(self.config.channels, name, None)
@@ -57,6 +59,7 @@ class ChannelManager:
                 channel = cls(section, self.bus)
                 channel.transcription_provider = transcription_provider
                 channel.transcription_api_key = transcription_key
+                channel._transcription_fallback_key = fallback_key
                 self.channels[name] = channel
                 logger.info("{} channel enabled", cls.display_name)
             except Exception as e:
@@ -66,9 +69,12 @@ class ChannelManager:
 
     def _resolve_transcription_key(self, provider: str) -> str:
         """Pick the API key for the configured transcription provider."""
-        if provider == "openai":
-            return self.config.providers.openai.api_key
-        return self.config.providers.groq.api_key
+        try:
+            if provider == "openai":
+                return self.config.providers.openai.api_key
+            return self.config.providers.groq.api_key
+        except AttributeError:
+            return ""
 
     def _validate_allow_from(self) -> None:
         for name, ch in self.channels.items():