diff --git a/src/Backend/AutopilotMonitor.Functions.Tests/DelegatedBoundedAggregateTests.cs b/src/Backend/AutopilotMonitor.Functions.Tests/DelegatedBoundedAggregateTests.cs
new file mode 100644
index 00000000..d411afdf
--- /dev/null
+++ b/src/Backend/AutopilotMonitor.Functions.Tests/DelegatedBoundedAggregateTests.cs
@@ -0,0 +1,107 @@
+using System;
+using System.Collections.Generic;
+using System.Linq.Expressions;
+using System.Threading;
+using System.Threading.Tasks;
+using Azure;
+using Azure.Data.Tables;
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// Security guard for the delegated ("MSP") bounded aggregate. GetAllSessionsPageAsync with a non-null
+/// allowedTenantIds must NEVER fall back to the unbounded primary-table scan when the managed set resolves
+/// to no in-config tenants — otherwise /api/global/sessions (no tenantId), now admitted for a delegated
+/// caller, could leak ALL tenants' sessions when a managed tenant has no config row, config is momentarily
+/// empty, or a casing mismatch yields no overlap.
+/// </summary>
+public class DelegatedBoundedAggregateTests
+{
+    private const string ConfigTenant   = "11111111-1111-1111-1111-111111111111";
+    private const string ManagedTenant  = "22222222-2222-2222-2222-222222222222";
+
+    [Fact]
+    public async Task BoundedAggregate_EmptyManagedSet_ReturnsEmpty_NeverUnboundedScan()
+    {
+        // Config knows only ConfigTenant; the delegated caller manages a DIFFERENT tenant → bounded set is empty.
+        var configClient = MockTableClientReturning(new TableEntity(ConfigTenant, ""));
+        // Sessions table backs the UNBOUNDED fallback — it must never be queried for a bounded request.
+        var sessionsClient = MockTableClientReturning(new TableEntity("99999999-9999-9999-9999-999999999999", "leak"));
+        var indexClient = new Mock<TableClient>();
+
+        var storage = BuildStorage(configClient, sessionsClient, indexClient);
+
+        var page = await storage.GetAllSessionsPageAsync(
+            tenantIdFilter: null, days: null, pageSize: 10, continuation: null,
+            allowedTenantIds: new[] { ManagedTenant });
+
+        Assert.Empty(page.Items);
+        AssertNeverQueried(sessionsClient);
+    }
+
+    [Fact]
+    public async Task UnboundedAggregate_EmptyConfig_StillUsesPrimaryTableFallback()
+    {
+        // Sanity: with allowedTenantIds == null (GA all-tenants) and empty config, the legacy fallback DOES run —
+        // proving it is the bounded guard, not some unrelated gate, that suppresses the scan above.
+        var configClient = MockTableClientReturning();
+        var sessionsClient = MockTableClientReturning();
+        var indexClient = new Mock<TableClient>();
+
+        var storage = BuildStorage(configClient, sessionsClient, indexClient);
+
+        var page = await storage.GetAllSessionsPageAsync(
+            tenantIdFilter: null, days: null, pageSize: 10, continuation: null, allowedTenantIds: null);
+
+        Assert.Empty(page.Items);
+        sessionsClient.Verify(c => c.QueryAsync<TableEntity>(
+            It.IsAny<string>(), It.IsAny<int?>(), It.IsAny<IEnumerable<string>>(), It.IsAny<CancellationToken>()),
+            Times.AtLeastOnce());
+    }
+
+    // ── helpers ──────────────────────────────────────────────────────────────
+
+    private static TableStorageService BuildStorage(
+        Mock<TableClient> config, Mock<TableClient> sessions, Mock<TableClient> index)
+    {
+        var serviceClient = new Mock<TableServiceClient>();
+        serviceClient.Setup(s => s.GetTableClient(Constants.TableNames.TenantConfiguration)).Returns(config.Object);
+        serviceClient.Setup(s => s.GetTableClient(Constants.TableNames.Sessions)).Returns(sessions.Object);
+        serviceClient.Setup(s => s.GetTableClient(Constants.TableNames.SessionsIndex)).Returns(index.Object);
+        return new TableStorageService(serviceClient.Object, NullLogger<TableStorageService>.Instance);
+    }
+
+    /// <summary>Mocks both QueryAsync overloads (string + expression filter) to return the given rows.</summary>
+    private static Mock<TableClient> MockTableClientReturning(params TableEntity[] rows)
+    {
+        var m = new Mock<TableClient>();
+        m.Setup(c => c.QueryAsync<TableEntity>(
+                It.IsAny<string>(), It.IsAny<int?>(), It.IsAny<IEnumerable<string>>(), It.IsAny<CancellationToken>()))
+            .Returns(() => AsAsyncPageable(rows));
+        m.Setup(c => c.QueryAsync<TableEntity>(
+                It.IsAny<Expression<Func<TableEntity, bool>>>(), It.IsAny<int?>(), It.IsAny<IEnumerable<string>>(), It.IsAny<CancellationToken>()))
+            .Returns(() => AsAsyncPageable(rows));
+        return m;
+    }
+
+    private static void AssertNeverQueried(Mock<TableClient> client)
+    {
+        client.Verify(c => c.QueryAsync<TableEntity>(
+            It.IsAny<string>(), It.IsAny<int?>(), It.IsAny<IEnumerable<string>>(), It.IsAny<CancellationToken>()),
+            Times.Never());
+        client.Verify(c => c.QueryAsync<TableEntity>(
+            It.IsAny<Expression<Func<TableEntity, bool>>>(), It.IsAny<int?>(), It.IsAny<IEnumerable<string>>(), It.IsAny<CancellationToken>()),
+            Times.Never());
+    }
+
+    private static AsyncPageable<TableEntity> AsAsyncPageable(TableEntity[] entities)
+    {
+        var page = Page<TableEntity>.FromValues(entities, continuationToken: null, new Mock<Response>().Object);
+        return AsyncPageable<TableEntity>.FromPages(new[] { page });
+    }
+}
diff --git a/src/Backend/AutopilotMonitor.Functions/Services/TableStorageService.Sessions.cs b/src/Backend/AutopilotMonitor.Functions/Services/TableStorageService.Sessions.cs
index 4059aa62..9950c069 100644
--- a/src/Backend/AutopilotMonitor.Functions/Services/TableStorageService.Sessions.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Services/TableStorageService.Sessions.cs
@@ -1101,6 +1101,13 @@ namespace AutopilotMonitor.Functions.Services
 
                 if (tenantIds.Count == 0 && string.IsNullOrEmpty(cursor))
                 {
+                    // A BOUNDED (delegated/MSP) request must NEVER fall back to the unbounded primary-table
+                    // scan: an empty allowed set (managed tenant has no config row, config momentarily empty,
+                    // or a casing mismatch) means "none of YOUR tenants" → empty page, not ALL tenants. The
+                    // primary-table fallback is only the GA all-tenants safety net for a fresh/empty config.
+                    if (allowedTenantIds != null)
+                        return (new List<SessionSummary>(), false, null);
+
                     var fallback = await FetchAllSessionsFromPrimaryTableInternalAsync(maxResults, days);
                     return (fallback.Sessions, fallback.HasMore, NextCursor: null);
                 }
diff --git a/src/Web/autopilot-monitor-web/app/analyze-rules/page.tsx b/src/Web/autopilot-monitor-web/app/analyze-rules/page.tsx
index 684427b4..edae2e39 100644
--- a/src/Web/autopilot-monitor-web/app/analyze-rules/page.tsx
+++ b/src/Web/autopilot-monitor-web/app/analyze-rules/page.tsx
@@ -14,7 +14,7 @@ import { RuleFilterBar } from "@/components/rules/RuleFilterBar";
 import { EmptyState } from "@/components/rules/EmptyState";
 import { FormJsonToggle, JsonModeToggleButtons } from "@/components/rules/FormJsonToggle";
 import { useAuthenticatedFetch, useNotificationMessages, useGlobalAdminScope } from "@/hooks";
-import { GlobalAdminBanner } from "@/components/GlobalAdminBanner";
+import { GlobalAdminBanner, globalAdminSubtitle } from "@/components/GlobalAdminBanner";
 import { TenantScopeSelector } from "@/components/TenantScopeSelector";
 
 import { isTemplateRule } from "@/lib/analyzeRuleTabs";
@@ -407,7 +407,7 @@ export default function AnalyzeRulesPage() {
   return (
     <ProtectedRoute>
       <div className="min-h-screen bg-gray-50">
-        <GlobalAdminBanner show={scope.isGlobalAdmin} delegated={scope.isDelegatedScope} />
+        <GlobalAdminBanner show={scope.isGlobalAdmin} delegated={scope.isDelegatedScope} subtitle={globalAdminSubtitle(scope)} />
         {/* Header */}
         <header className="bg-white shadow">
           <div className="max-w-7xl mx-auto py-6 px-4 sm:px-6 lg:px-8">
diff --git a/src/Web/autopilot-monitor-web/app/gather-rules/page.tsx b/src/Web/autopilot-monitor-web/app/gather-rules/page.tsx
index a3339789..c02aa0e6 100644
--- a/src/Web/autopilot-monitor-web/app/gather-rules/page.tsx
+++ b/src/Web/autopilot-monitor-web/app/gather-rules/page.tsx
@@ -14,7 +14,7 @@ import { RuleFilterBar } from "@/components/rules/RuleFilterBar";
 import { EmptyState } from "@/components/rules/EmptyState";
 import { FormJsonToggle, JsonModeToggleButtons } from "@/components/rules/FormJsonToggle";
 import { useAuthenticatedFetch, useNotificationMessages, useGlobalAdminScope } from "@/hooks";
-import { GlobalAdminBanner } from "@/components/GlobalAdminBanner";
+import { GlobalAdminBanner, globalAdminSubtitle } from "@/components/GlobalAdminBanner";
 import { TenantScopeSelector } from "@/components/TenantScopeSelector";
 import { GatherRule, NewRuleForm, EMPTY_FORM, CATEGORY_COLORS } from "./types";
 import { GatherRuleFormFields } from "./components/GatherRuleFormFields";
@@ -362,7 +362,7 @@ export default function GatherRulesPage() {
   return (
     <ProtectedRoute>
       <div className="min-h-screen bg-gray-50">
-        <GlobalAdminBanner show={scope.isGlobalAdmin} delegated={scope.isDelegatedScope} />
+        <GlobalAdminBanner show={scope.isGlobalAdmin} delegated={scope.isDelegatedScope} subtitle={globalAdminSubtitle(scope)} />
         {/* Header */}
         <header className="bg-white shadow">
           <div className="max-w-7xl mx-auto py-6 px-4 sm:px-6 lg:px-8">
diff --git a/src/Web/autopilot-monitor-web/app/sla/page.tsx b/src/Web/autopilot-monitor-web/app/sla/page.tsx
index 181030a9..7f88a6d6 100644
--- a/src/Web/autopilot-monitor-web/app/sla/page.tsx
+++ b/src/Web/autopilot-monitor-web/app/sla/page.tsx
@@ -23,7 +23,7 @@ const AppLineChart = dynamic(() => import("@/components/charts/AppLineChart"), {
 });
 import { trackEvent } from "@/lib/appInsights";
 import { useGlobalAdminScope } from "@/hooks";
-import { GlobalAdminBanner } from "@/components/GlobalAdminBanner";
+import { GlobalAdminBanner, globalAdminSubtitle } from "@/components/GlobalAdminBanner";
 import { TenantScopeSelector } from "@/components/TenantScopeSelector";
 import Link from "next/link";
 
@@ -182,7 +182,7 @@ export default function SlaPage() {
   return (
     <ProtectedRoute>
       <div className="min-h-screen bg-gray-50 dark:bg-gray-900">
-        <GlobalAdminBanner show={scope.isGlobalAdmin} delegated={scope.isDelegatedScope} />
+        <GlobalAdminBanner show={scope.isGlobalAdmin} delegated={scope.isDelegatedScope} subtitle={globalAdminSubtitle(scope)} />
         {/* Header */}
         <header className="bg-white dark:bg-gray-800 shadow">
           <div className="max-w-7xl mx-auto py-6 px-4 sm:px-6 lg:px-8">
diff --git a/src/Web/autopilot-monitor-web/app/usage-metrics/page.tsx b/src/Web/autopilot-monitor-web/app/usage-metrics/page.tsx
index 10139d58..5cef24b9 100644
--- a/src/Web/autopilot-monitor-web/app/usage-metrics/page.tsx
+++ b/src/Web/autopilot-monitor-web/app/usage-metrics/page.tsx
@@ -8,7 +8,7 @@ import { ProtectedRoute } from '../../components/ProtectedRoute';
 import { api } from "@/lib/api";
 import { authenticatedFetch, TokenExpiredError } from "@/lib/authenticatedFetch";
 import { useGlobalAdminScope } from "@/hooks";
-import { GlobalAdminBanner } from "@/components/GlobalAdminBanner";
+import { GlobalAdminBanner, globalAdminSubtitle } from "@/components/GlobalAdminBanner";
 import { TenantScopeSelector } from "@/components/TenantScopeSelector";
 
 interface SessionMetrics {
@@ -171,7 +171,7 @@ export default function UsageMetricsPage() {
   return (
 <ProtectedRoute>
     <div className="min-h-screen bg-gray-50">
-      <GlobalAdminBanner show={scope.isGlobalAdmin} delegated={scope.isDelegatedScope} />
+      <GlobalAdminBanner show={scope.isGlobalAdmin} delegated={scope.isDelegatedScope} subtitle={globalAdminSubtitle(scope)} />
       <header className="bg-white shadow">
         <div className="max-w-7xl mx-auto py-6 px-4 sm:px-6 lg:px-8">
           <div className="flex items-center justify-between">