diff --git a/apps/machine/.env.example b/apps/machine/.env.example
index 8124aa4..1bc2c2e 100644
--- a/apps/machine/.env.example
+++ b/apps/machine/.env.example
@@ -49,6 +49,13 @@ VITE_ATM_PRIVATE_KEY=
 # (manual dispense, remote management). Decoupled from Lightning.Pub identity.
 # VITE_OPERATOR_PUBKEYS=abcd1234...,ef567890...
 
+# =============================================================================
+# Maintenance Mode
+# =============================================================================
+
+# Show "Under Service" screen and block all transactions
+# VITE_MAINTENANCE_MODE=true
+
 # =============================================================================
 # Mock Fallback (Production Safety)
 # =============================================================================
diff --git a/apps/machine/electron/main.ts b/apps/machine/electron/main.ts
index 04c61db..875cf73 100644
--- a/apps/machine/electron/main.ts
+++ b/apps/machine/electron/main.ts
@@ -187,6 +187,9 @@ ipcMain.handle('get-config', () => {
 
     // Operator identity (comma-separated hex pubkeys)
     operatorPubkeys: process.env.VITE_OPERATOR_PUBKEYS || '',
+
+    // Maintenance mode — show "out of service" screen
+    maintenanceMode: process.env.VITE_MAINTENANCE_MODE === 'true',
   }
 })
 
diff --git a/apps/machine/electron/preload.ts b/apps/machine/electron/preload.ts
index 952ede7..17f3ab4 100644
--- a/apps/machine/electron/preload.ts
+++ b/apps/machine/electron/preload.ts
@@ -26,6 +26,7 @@ export interface RuntimeConfig {
   cassettes?: string
   allowMockFallback: boolean
   operatorPubkeys: string
+  maintenanceMode: boolean
 }
 
 /**
diff --git a/apps/machine/src/App.vue b/apps/machine/src/App.vue
index 4d06d80..c0d0bb1 100644
--- a/apps/machine/src/App.vue
+++ b/apps/machine/src/App.vue
@@ -33,6 +33,16 @@ onMounted(async () => {
     })
   }
 
+  // Check maintenance mode before initializing anything
+  const config = isElectron ? await window.electronAPI?.getConfig() : null
+  const maintenanceMode =
+    config?.maintenanceMode || import.meta.env.VITE_MAINTENANCE_MODE === 'true'
+
+  if (maintenanceMode) {
+    atmStore.initError = 'maintenance'
+    return
+  }
+
   try {
     if (isElectron) {
       await atmStore.initializeForProduction()
@@ -88,11 +98,20 @@ function toggleLiveServices() {
         <line x1="12" y1="9" x2="12" y2="13" />
         <line x1="12" y1="17" x2="12.01" y2="17" />
       </svg>
-      <h1 class="text-2xl lg:text-[3.5rem] font-bold">ATM Unavailable</h1>
+      <h1 class="text-2xl lg:text-[3.5rem] font-bold">
+        {{ atmStore.initError === 'maintenance' ? 'Under Service' : 'ATM Unavailable' }}
+      </h1>
       <p class="max-w-md text-center text-base lg:text-2xl text-muted-foreground">
-        This machine is temporarily out of service. Please try again later or use another machine.
+        {{
+          atmStore.initError === 'maintenance'
+            ? 'This machine is currently being serviced. We will be back shortly.'
+            : 'This machine is temporarily out of service. Please try again later or use another machine.'
+        }}
       </p>
-      <p v-if="atmStore.debugMode" class="max-w-lg text-center font-mono text-sm text-destructive">
+      <p
+        v-if="atmStore.debugMode && atmStore.initError !== 'maintenance'"
+        class="max-w-lg text-center font-mono text-sm text-destructive"
+      >
         {{ atmStore.initError }}
       </p>
     </div>
diff --git a/apps/machine/src/types/electron.d.ts b/apps/machine/src/types/electron.d.ts
index bccb0e8..7e13fb7 100644
--- a/apps/machine/src/types/electron.d.ts
+++ b/apps/machine/src/types/electron.d.ts
@@ -15,6 +15,7 @@ export interface RuntimeConfig {
   cassettes?: string
   allowMockFallback: boolean
   operatorPubkeys: string
+  maintenanceMode: boolean
 }
 
 export interface AtmSecrets {