diff --git a/src/components/layout/Navbar.vue b/src/components/layout/Navbar.vue
index 08ded0c..07fbba1 100644
--- a/src/components/layout/Navbar.vue
+++ b/src/components/layout/Navbar.vue
@@ -33,13 +33,12 @@ const { navigation: modularNavigation, userMenuItems } = useModularNavigation()
 
 const navigation = modularNavigation
 
-// Compute total wallet balance
-const totalBalance = computed(() => {
-  if (!auth.currentUser.value?.wallets) return 0
+// Get PaymentService from DI for centralized wallet balance
+const paymentService = tryInjectService(SERVICE_TOKENS.PAYMENT_SERVICE) as any
 
-  return auth.currentUser.value.wallets.reduce((total, wallet) => {
-    return total + (wallet.balance_msat || 0)
-  }, 0)
+// Use PaymentService for total wallet balance
+const totalBalance = computed(() => {
+  return paymentService?.totalBalance || 0
 })
 
 // Try to get chat service from DI (may not be available if chat module not loaded)
diff --git a/src/core/services/PaymentService.ts b/src/core/services/PaymentService.ts
index c19c4bb..277fabd 100644
--- a/src/core/services/PaymentService.ts
+++ b/src/core/services/PaymentService.ts
@@ -59,6 +59,15 @@ export class PaymentService extends BaseService {
     return this.authService?.user?.value?.wallets || []
   }
 
+  /**
+   * Get total balance across all user wallets in millisatoshis
+   */
+  get totalBalance(): number {
+    return this.userWallets.reduce((total: number, wallet: any) => {
+      return total + (wallet.balance_msat || 0)
+    }, 0)
+  }
+
   /**
    * Check if user has any wallet with balance
    */
diff --git a/src/modules/market/components/CreateProductDialog.vue b/src/modules/market/components/CreateProductDialog.vue
index d03cff1..de94285 100644
--- a/src/modules/market/components/CreateProductDialog.vue
+++ b/src/modules/market/components/CreateProductDialog.vue
@@ -232,6 +232,7 @@ const emit = defineEmits<{
 
 // Services
 const nostrmarketAPI = injectService(SERVICE_TOKENS.NOSTRMARKET_API) as NostrmarketAPI
+const paymentService = injectService(SERVICE_TOKENS.PAYMENT_SERVICE) as any
 const toast = useToast()
 
 // Local state
@@ -336,8 +337,13 @@ const updateProduct = async (formData: any) => {
       }
     }
 
+    const adminKey = paymentService.getPreferredWalletAdminKey()
+    if (!adminKey) {
+      throw new Error('No wallet admin key available')
+    }
+
     const updatedProduct = await nostrmarketAPI.updateProduct(
-      currentUser.wallets[0].adminkey,
+      adminKey,
       props.product.id,
       productData
     )
@@ -398,8 +404,13 @@ const createProduct = async (formData: any) => {
       }
     }
 
+    const adminKey = paymentService.getPreferredWalletAdminKey()
+    if (!adminKey) {
+      throw new Error('No wallet admin key available')
+    }
+
     const newProduct = await nostrmarketAPI.createProduct(
-      currentUser.wallets[0].adminkey,
+      adminKey,
       productData
     )
 
diff --git a/src/modules/market/components/CreateStoreDialog.vue b/src/modules/market/components/CreateStoreDialog.vue
index 5a65074..613c005 100644
--- a/src/modules/market/components/CreateStoreDialog.vue
+++ b/src/modules/market/components/CreateStoreDialog.vue
@@ -269,6 +269,7 @@ const emit = defineEmits<{
 
 // Services
 const nostrmarketAPI = injectService(SERVICE_TOKENS.NOSTRMARKET_API) as NostrmarketAPI
+const paymentService = injectService(SERVICE_TOKENS.PAYMENT_SERVICE) as any
 const toast = useToast()
 
 // Local state
@@ -342,8 +343,11 @@ const loadAvailableZones = async () => {
   const currentUser = auth.currentUser?.value
   if (!currentUser?.wallets?.length) return
   
+  const inkey = paymentService.getPreferredWalletInvoiceKey()
+  if (!inkey) return
+
   try {
-    const zones = await nostrmarketAPI.getZones(currentUser.wallets[0].inkey)
+    const zones = await nostrmarketAPI.getZones(inkey)
     availableZones.value = zones
     
     // Auto-select the first available zone to make form valid
@@ -370,9 +374,14 @@ const addNewZone = async () => {
     return
   }
 
+  const adminKey = paymentService.getPreferredWalletAdminKey()
+  if (!adminKey) {
+    throw new Error('No wallet admin key available')
+  }
+
   try {
     const createdZone = await nostrmarketAPI.createZone(
-      currentUser.wallets[0].adminkey,
+      adminKey,
       {
         name: newZone.name!,
         currency: values.currency!,
@@ -418,9 +427,14 @@ const createStore = async (formData: any) => {
       selectedZones.includes(zone.id)
     )
 
+    const wallet = paymentService.getPreferredWallet()
+    if (!wallet) {
+      throw new Error('No wallet available')
+    }
+
     const stallData: CreateStallRequest = {
       name,
-      wallet: currentUser.wallets[0].id,
+      wallet: wallet.id,
       currency,
       shipping_zones: selectedZoneData,
       config: {
@@ -428,8 +442,13 @@ const createStore = async (formData: any) => {
       }
     }
 
+    const adminKey = paymentService.getPreferredWalletAdminKey()
+    if (!adminKey) {
+      throw new Error('No wallet admin key available')
+    }
+
     const newStall = await nostrmarketAPI.createStall(
-      currentUser.wallets[0].adminkey,
+      adminKey,
       stallData
     )
 
diff --git a/src/modules/market/components/MerchantStore.vue b/src/modules/market/components/MerchantStore.vue
index b4c9b6c..854ca9a 100644
--- a/src/modules/market/components/MerchantStore.vue
+++ b/src/modules/market/components/MerchantStore.vue
@@ -353,6 +353,7 @@ import StoreCard from './StoreCard.vue'
 const router = useRouter()
 const marketStore = useMarketStore()
 const nostrmarketAPI = injectService(SERVICE_TOKENS.NOSTRMARKET_API) as NostrmarketAPI
+const paymentService = injectService(SERVICE_TOKENS.PAYMENT_SERVICE) as any
 const toast = useToast()
 
 // Local state
@@ -473,8 +474,15 @@ const loadStallsList = async () => {
   }
   
   isLoadingStalls.value = true
+
+  const inkey = paymentService.getPreferredWalletInvoiceKey()
+  if (!inkey) {
+    console.error('No wallet invoice key available')
+    return
+  }
+
   try {
-    const stalls = await nostrmarketAPI.getStalls(currentUser.wallets[0].inkey)
+    const stalls = await nostrmarketAPI.getStalls(inkey)
     userStalls.value = stalls || []
     
     // If there are stalls but no active one selected, select the first
@@ -496,9 +504,16 @@ const loadStallProducts = async () => {
   if (!currentUser?.wallets?.length) return
   
   isLoadingProducts.value = true
+
+  const inkey = paymentService.getPreferredWalletInvoiceKey()
+  if (!inkey) {
+    console.error('No wallet invoice key available')
+    return
+  }
+
   try {
     const products = await nostrmarketAPI.getProducts(
-      currentUser.wallets[0].inkey, 
+      inkey,
       activeStall.value.id!
     )
     stallProducts.value = products || []
diff --git a/src/modules/wallet/views/WalletPage.vue b/src/modules/wallet/views/WalletPage.vue
index d63ed30..462f46d 100644
--- a/src/modules/wallet/views/WalletPage.vue
+++ b/src/modules/wallet/views/WalletPage.vue
@@ -28,13 +28,8 @@ const isGeneratingQR = ref(false)
 const transactions = computed(() => walletService?.transactions?.value || [])
 const isLoading = computed(() => walletService?.isLoading?.value || false)
 const error = computed(() => walletService?.error?.value)
-const currentUser = computed(() => authService?.currentUser?.value)
-const totalBalance = computed(() => {
-  if (!currentUser.value?.wallets) return 0
-  return currentUser.value.wallets.reduce((total: number, wallet: any) => {
-    return total + (wallet.balance_msat || 0)
-  }, 0)
-})
+// Use PaymentService for centralized balance calculation
+const totalBalance = computed(() => paymentService?.totalBalance || 0)
 
 const payLinks = computed(() => walletService?.payLinks?.value || [])
 const firstPayLink = computed(() => payLinks.value[0] || null)