diff --git a/packages/web/src/components/layout/ChannelSidebar.tsx b/packages/web/src/components/layout/ChannelSidebar.tsx
index 92065502..20d6f41a 100644
--- a/packages/web/src/components/layout/ChannelSidebar.tsx
+++ b/packages/web/src/components/layout/ChannelSidebar.tsx
@@ -15,6 +15,7 @@ import { getActiveRoom } from '../../hooks/useLiveKit';
 import { AudioManager } from '../../audio/AudioManager';
 import { hasPermissionBit, PermissionBits } from '../../utils/permissions';
 import { parseFederatedUsername, isSelf } from '../../utils/identity';
+import { joinVoiceChannel } from '../../utils/voice';
 
 export function ChannelSidebar() {
   const servers = useServerStore((s) => s.servers);
@@ -29,7 +30,6 @@ export function ChannelSidebar() {
   const members = useServerStore((s) => s.members);
   const currentVoiceChannelId = useVoiceStore((s) => s.currentVoiceChannelId);
   const activeDmCall = useVoiceStore((s) => s.activeDmCall);
-  const setCurrentVoiceChannel = useVoiceStore((s) => s.setCurrentVoiceChannel);
   const isMuted = useVoiceStore((s) => s.isMuted);
   const isDeafened = useVoiceStore((s) => s.isDeafened);
   const toggleMic = useVoiceStore((s) => s.toggleMic);
@@ -104,8 +104,7 @@ export function ChannelSidebar() {
       navigate(`/channels/${currentServerId}/${channelId}`);
       return;
     }
-    setCurrentVoiceChannel(channelId);
-    wsSend({ type: 'voice_join', channelId }, getChannelOrigin(channelId));
+    joinVoiceChannel(channelId);
     navigate(`/channels/${currentServerId}/${channelId}`);
   };
 
diff --git a/packages/web/src/components/layout/MainContent.tsx b/packages/web/src/components/layout/MainContent.tsx
index c2df75f4..dd212a87 100644
--- a/packages/web/src/components/layout/MainContent.tsx
+++ b/packages/web/src/components/layout/MainContent.tsx
@@ -1,5 +1,5 @@
 import React, { useEffect, useRef, useState, useCallback } from 'react';
-import { useServerStore, getChannelOrigin } from '../../stores/serverStore';
+import { useServerStore } from '../../stores/serverStore';
 import { useChatStore } from '../../stores/chatStore';
 import { useUIStore } from '../../stores/uiStore';
 import { useAuthStore } from '../../stores/authStore';
@@ -15,6 +15,7 @@ import { useVoiceStore } from '../../stores/voiceStore';
 import { wsSend } from '../../hooks/useWebSocket';
 import { MemberListToggleButton } from './MemberListToggleButton';
 import { isSelf } from '../../utils/identity';
+import { joinVoiceChannel } from '../../utils/voice';
 
 export function MainContent() {
   // 1. ALL HOOKS AT THE TOP
@@ -258,10 +259,7 @@ export function MainContent() {
               <p className="text-txt-tertiary text-[15px]">No one is currently in this voice channel.</p>
             </div>
             <button
-              onClick={() => {
-                useVoiceStore.getState().setCurrentVoiceChannel(currentChannelId);
-                wsSend({ type: 'voice_join', channelId: currentChannelId }, getChannelOrigin(currentChannelId));
-              }}
+              onClick={() => joinVoiceChannel(currentChannelId)}
               className="relative z-10 px-8 py-3 bg-accent-primary hover:bg-accent-primary-hover text-white font-semibold rounded-full transition-all text-[15px] shadow-[0_4px_20px_rgba(124,108,246,0.3)]"
             >
               Join Voice
diff --git a/packages/web/src/hooks/useWebSocket.ts b/packages/web/src/hooks/useWebSocket.ts
index 4b21d9c7..e3422f75 100644
--- a/packages/web/src/hooks/useWebSocket.ts
+++ b/packages/web/src/hooks/useWebSocket.ts
@@ -1,6 +1,6 @@
 import React, { useEffect, useRef } from 'react';
 import { useAuthStore } from '../stores/authStore';
-import { useServerStore } from '../stores/serverStore';
+import { useServerStore, getChannelOrigin } from '../stores/serverStore';
 import { useChatStore } from '../stores/chatStore';
 import { useVoiceStore } from '../stores/voiceStore';
 import { useSocialStore } from '../stores/socialStore';
@@ -162,13 +162,17 @@ function handleEvent(origin: string, event: ServerEvent): void {
         }
       }
 
-      // Re-register in voice channel if we're still connected to LiveKit (home only)
-      if (isHome) {
+      // Re-register in voice channel if we're still connected to LiveKit
+      // Origin-aware: re-sends voice_join only if the voice channel belongs to this origin
+      {
         const { currentVoiceChannelId, isMuted: curMuted, isDeafened: curDeafened, isCameraOn: curCamera, isScreenSharing: curScreen } = useVoiceStore.getState();
         if (currentVoiceChannelId) {
-          console.log('[WebSocket] Re-syncing voice status on reconnect:', { currentVoiceChannelId, curMuted, curDeafened, curCamera, curScreen });
-          wsSend({ type: 'voice_join', channelId: currentVoiceChannelId });
-          wsSend({ type: 'voice_status', isMuted: curMuted, isDeafened: curDeafened, isCameraOn: curCamera, isScreenSharing: curScreen });
+          const voiceOrigin = getChannelOrigin(currentVoiceChannelId);
+          if (voiceOrigin === origin) {
+            console.log('[WebSocket] Re-syncing voice status on reconnect:', { currentVoiceChannelId, origin, curMuted, curDeafened, curCamera, curScreen });
+            wsSend({ type: 'voice_join', channelId: currentVoiceChannelId }, origin);
+            wsSend({ type: 'voice_status', isMuted: curMuted, isDeafened: curDeafened, isCameraOn: curCamera, isScreenSharing: curScreen }, origin);
+          }
         }
       }
 
diff --git a/packages/web/src/utils/voice.ts b/packages/web/src/utils/voice.ts
new file mode 100644
index 00000000..209afb90
--- /dev/null
+++ b/packages/web/src/utils/voice.ts
@@ -0,0 +1,26 @@
+import { useVoiceStore } from '../stores/voiceStore';
+import { getChannelOrigin } from '../stores/serverStore';
+import { wsSend } from '../hooks/useWebSocket';
+
+/**
+ * Centralized voice channel join that handles cross-instance cleanup.
+ * When switching from a channel on Instance A to one on Instance B,
+ * this sends an explicit voice_leave to Instance A first so it
+ * broadcasts a leave event and the client cleans up stale voice state.
+ */
+export function joinVoiceChannel(channelId: string): void {
+  const { currentVoiceChannelId, setCurrentVoiceChannel } = useVoiceStore.getState();
+  if (currentVoiceChannelId === channelId) return;
+
+  // Leave old instance if switching cross-origin
+  if (currentVoiceChannelId) {
+    const oldOrigin = getChannelOrigin(currentVoiceChannelId);
+    const newOrigin = getChannelOrigin(channelId);
+    if (oldOrigin !== newOrigin) {
+      wsSend({ type: 'voice_leave' }, oldOrigin);
+    }
+  }
+
+  setCurrentVoiceChannel(channelId);
+  wsSend({ type: 'voice_join', channelId }, getChannelOrigin(channelId));
+}