diff --git a/scripts/ralph/prd.json b/scripts/ralph/prd.json
index 8ceabe3..95fb882 100644
--- a/scripts/ralph/prd.json
+++ b/scripts/ralph/prd.json
@@ -84,8 +84,8 @@
         "npm run typecheck passes",
         "Verify in browser: Page shows detailed invoices table with Clienți/Furnizori tabs"
       ],
-      "passes": false,
-      "notes": "Creează fișier nou, adaugă rută în src/modules/reports/router/reports.routes.js"
+      "passes": true,
+      "notes": "Completed in iteration 3"
     },
     {
       "id": "US-604",
diff --git a/scripts/ralph/progress.txt b/scripts/ralph/progress.txt
index 93d06f5..cfcddd6 100644
--- a/scripts/ralph/progress.txt
+++ b/scripts/ralph/progress.txt
@@ -255,3 +255,9 @@ PRD: tasks/prd-ui-fixes-phase6.md
 [2026-01-13 16:02:34] Working on story: US-602
 [2026-01-13 16:02:34] Running Claude... (log: /workspace/roa2web/scripts/ralph/logs/iteration_2_US-602.log)
 [2026-01-13 16:08:47] SUCCESS: Story US-602 passed!
+[2026-01-13 16:08:47] Changes committed
+[2026-01-13 16:08:47] Progress: 2/10 stories completed
+[2026-01-13 16:08:49] === Iteration 3/30 ===
+[2026-01-13 16:08:49] Working on story: US-603
+[2026-01-13 16:08:49] Running Claude... (log: /workspace/roa2web/scripts/ralph/logs/iteration_3_US-603.log)
+[2026-01-13 16:11:33] SUCCESS: Story US-603 passed!
diff --git a/src/modules/reports/views/DetailedInvoicesView.vue b/src/modules/reports/views/DetailedInvoicesView.vue
index dde5acb..494ba6f 100644
--- a/src/modules/reports/views/DetailedInvoicesView.vue
+++ b/src/modules/reports/views/DetailedInvoicesView.vue
@@ -1,25 +1,65 @@
 <template>
   <!-- US-501: Mobile Top Bar -->
-  <!-- US-510: Dynamic title based on route type -->
+  <!-- US-603: Title is now "Facturi Detaliate" with tabs below -->
   <MobileTopBar
     v-if="isMobile"
-    :title="pageTitle"
+    title="Facturi Detaliate"
     :show-back="true"
     :actions="topBarActions"
     @back-click="goBack"
     @action-click="handleTopBarAction"
   />
 
+  <!-- US-603: Mobile Tabs for Clienți/Furnizori -->
+  <div v-if="isMobile" class="mobile-tabs-container">
+    <div class="mobile-tabs">
+      <button
+        class="mobile-tab"
+        :class="{ active: activeTab === 'clients' }"
+        @click="switchTab('clients')"
+      >
+        <span class="tab-label">Clienți</span>
+      </button>
+      <button
+        class="mobile-tab"
+        :class="{ active: activeTab === 'suppliers' }"
+        @click="switchTab('suppliers')"
+      >
+        <span class="tab-label">Furnizori</span>
+      </button>
+    </div>
+  </div>
+
   <!-- US-501: Export Menu (for mobile export dropdown) -->
   <Menu ref="exportMenu" :model="exportMenuItems" :popup="true" />
 
-  <main class="main-content" :class="{ 'mobile-layout': isMobile }">
+  <main class="main-content" :class="{ 'mobile-layout': isMobile, 'has-tabs': isMobile }">
     <div class="app-container">
       <!-- Page Header - only on desktop -->
-      <!-- US-510: Dynamic title based on route type -->
+      <!-- US-603: Desktop header with tabs -->
       <div v-if="!isMobile" class="page-header">
-        <h1 class="page-title">{{ pageTitle }}</h1>
-        <p class="page-subtitle">{{ pageSubtitle }}</p>
+        <h1 class="page-title">Facturi Detaliate</h1>
+        <p class="page-subtitle">Vizualizare detaliată a facturilor clienți și furnizori</p>
+
+        <!-- US-603: Desktop Tabs for Clienți/Furnizori -->
+        <div class="desktop-tabs">
+          <button
+            class="desktop-tab"
+            :class="{ active: activeTab === 'clients' }"
+            @click="switchTab('clients')"
+          >
+            <i class="pi pi-users"></i>
+            <span>Clienți</span>
+          </button>
+          <button
+            class="desktop-tab"
+            :class="{ active: activeTab === 'suppliers' }"
+            @click="switchTab('suppliers')"
+          >
+            <i class="pi pi-truck"></i>
+            <span>Furnizori</span>
+          </button>
+        </div>
       </div>
 
       <!-- Loading state when no company selected -->
@@ -474,19 +514,31 @@ const dashboardStore = useDashboardStore()
 const companyStore = useCompanyStore()
 const periodStore = useAccountingPeriodStore()
 
-// US-510: Get invoice type from route meta (clients or suppliers)
-const invoiceType = computed(() => route.meta.invoiceType || 'clients')
+// US-603: Tab state - initialized from route meta or query param
+const activeTab = ref(route.query.tab === 'suppliers' ? 'suppliers' : (route.meta.invoiceType || 'clients'))
 
-// US-510: Dynamic page title and subtitle based on invoice type
-const pageTitle = computed(() => {
-  return invoiceType.value === 'clients' ? 'Facturi Clienți' : 'Facturi Furnizori'
-})
+// US-603: invoiceType is now derived from activeTab (not route meta)
+const invoiceType = computed(() => activeTab.value)
 
-const pageSubtitle = computed(() => {
-  return invoiceType.value === 'clients'
-    ? 'Vizualizare detaliată a facturilor clienți'
-    : 'Vizualizare detaliată a facturilor furnizori'
-})
+// US-603: Switch between Clienți/Furnizori tabs
+const switchTab = async (tab) => {
+  if (tab === activeTab.value) return
+
+  activeTab.value = tab
+
+  // Update URL query param without full navigation
+  router.replace({
+    query: {
+      ...route.query,
+      tab: tab === 'suppliers' ? 'suppliers' : undefined // Remove param if 'clients' (default)
+    }
+  })
+
+  // Reset pagination and reload data
+  firstRow.value = 0
+  expandedGroups.value.clear()
+  await loadDetailedData()
+}
 
 // Mobile detection
 const windowWidth = ref(window.innerWidth)
@@ -880,6 +932,104 @@ onUnmounted(() => {
   padding-bottom: 56px;
 }
 
+/* US-603: Extra padding when tabs are visible on mobile */
+.main-content.mobile-layout.has-tabs {
+  padding-top: calc(56px + 48px); /* MobileTopBar + tabs */
+}
+
+/* ================================================
+   US-603: Mobile Tabs (Clienți/Furnizori)
+   Material Design 3 inspired full-width tabs
+   ================================================ */
+
+.mobile-tabs-container {
+  position: fixed;
+  top: 56px; /* Below MobileTopBar */
+  left: 0;
+  right: 0;
+  z-index: var(--z-sticky);
+  background: var(--surface-card);
+  border-bottom: 1px solid var(--surface-border);
+}
+
+.mobile-tabs {
+  display: flex;
+  width: 100%;
+}
+
+.mobile-tab {
+  flex: 1;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: var(--space-md);
+  min-height: 48px;
+  background: transparent;
+  border: none;
+  border-bottom: 2px solid transparent;
+  cursor: pointer;
+  transition: all var(--transition-fast);
+  color: var(--text-color-secondary);
+  font-size: var(--text-sm);
+  font-weight: var(--font-medium);
+}
+
+.mobile-tab:active {
+  background: var(--surface-hover);
+}
+
+.mobile-tab.active {
+  color: var(--color-primary);
+  border-bottom-color: var(--color-primary);
+  font-weight: var(--font-semibold);
+}
+
+.tab-label {
+  text-transform: uppercase;
+  letter-spacing: 0.5px;
+}
+
+/* ================================================
+   US-603: Desktop Tabs (Clienți/Furnizori)
+   ================================================ */
+
+.desktop-tabs {
+  display: flex;
+  gap: var(--space-sm);
+  margin-top: var(--space-md);
+}
+
+.desktop-tab {
+  display: flex;
+  align-items: center;
+  gap: var(--space-sm);
+  padding: var(--space-sm) var(--space-lg);
+  background: var(--surface-hover);
+  border: 1px solid var(--surface-border);
+  border-radius: var(--radius-md);
+  cursor: pointer;
+  transition: all var(--transition-fast);
+  color: var(--text-color-secondary);
+  font-size: var(--text-sm);
+  font-weight: var(--font-medium);
+}
+
+.desktop-tab:hover {
+  background: var(--surface-card);
+  border-color: var(--color-primary);
+  color: var(--color-primary);
+}
+
+.desktop-tab.active {
+  background: var(--color-primary);
+  border-color: var(--color-primary);
+  color: var(--color-text-inverse);
+}
+
+.desktop-tab i {
+  font-size: var(--text-base);
+}
+
 /* App container */
 .app-container {
   max-width: 1400px;
diff --git a/src/router/index.js b/src/router/index.js
index 0c1226c..31484da 100644
--- a/src/router/index.js
+++ b/src/router/index.js
@@ -74,21 +74,11 @@ const routes = [
         meta: { requiresAuth: true, title: 'Analiză Scadențe - ROA2WEB' }
       },
       {
-        // US-601: Redirect base detailed-invoices path to clients (default)
+        // US-603: Single route for Detailed Invoices with tabs (Clienți/Furnizori)
         path: 'detailed-invoices',
-        redirect: '/reports/detailed-invoices/clients'
-      },
-      {
-        path: 'detailed-invoices/clients',
-        name: 'DetailedInvoicesClients',
+        name: 'DetailedInvoices',
         component: () => import('@reports/views/DetailedInvoicesView.vue'),
-        meta: { requiresAuth: true, title: 'Facturi Clienți - ROA2WEB', invoiceType: 'clients' }
-      },
-      {
-        path: 'detailed-invoices/suppliers',
-        name: 'DetailedInvoicesSuppliers',
-        component: () => import('@reports/views/DetailedInvoicesView.vue'),
-        meta: { requiresAuth: true, title: 'Facturi Furnizori - ROA2WEB', invoiceType: 'suppliers' }
+        meta: { requiresAuth: true, title: 'Facturi Detaliate - ROA2WEB' }
       }
     ]
   },