diff --git a/auth/oauth_microsoft.php b/auth/oauth_microsoft.php
index 88a008d..b0848c3 100644
--- a/auth/oauth_microsoft.php
+++ b/auth/oauth_microsoft.php
@@ -24,7 +24,7 @@ $tenantId = !empty($_GET['tenant_id'])
     : (!empty($savedSettings['tenant_id']) ? $savedSettings['tenant_id'] : fociz_env('MICROSOFT_TENANT_ID', 'common'));
 
 if (empty($clientId)) {
-    header('Location: /integrations.php?error=missing_ms_client_id');
+    header('Location: /integrations.php?error=' . urlencode('Vul eerst de Application (Client) ID en het Client Secret in bij de Outlook instellingen om te koppelen met Microsoft 365.'));
     exit;
 }
 
diff --git a/integrations.php b/integrations.php
index 80fa5b5..70825e0 100644
--- a/integrations.php
+++ b/integrations.php
@@ -3,12 +3,13 @@
  * Fociz Integraties Hub (Microsoft Outlook, Microsoft Teams, Atlassian Jira)
  */
 
-require_once __DIR__ . '/includes/header.php';
+require_once __DIR__ . '/includes/auth.php';
 require_once __DIR__ . '/includes/integrations/microsoft.php';
 require_once __DIR__ . '/includes/integrations/jira.php';
 
+$user = require_auth();
 $db = get_db_connection();
-$userId = $currentUser['id'];
+$userId = $user['id'];
 
 $message = null;
 $messageType = 'success';
@@ -22,7 +23,7 @@ if (!empty($_GET['success'])) {
     $messageType = 'error';
 }
 
-// POST Verwerking
+// POST Verwerking VÓÓR het inladen van header.php zodat HTTP redirects altijd werken
 if ($_SERVER['REQUEST_METHOD'] === 'POST') {
     $provider = strtoupper(trim($_POST['provider'] ?? ''));
     $action   = $_POST['action'] ?? 'save';
@@ -31,18 +32,21 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
     if ($action === 'disconnect') {
         if ($provider === 'OUTLOOK') {
             microsoft_disconnect($userId);
-            $message = "Microsoft Outlook is succesvol ontkoppeld.";
+            header('Location: /integrations.php?success=' . urlencode('Microsoft Outlook is succesvol ontkoppeld.'));
+            exit;
         } elseif ($provider === 'JIRA') {
             jira_disconnect($userId);
-            $message = "Atlassian Jira is succesvol ontkoppeld.";
+            header('Location: /integrations.php?success=' . urlencode('Atlassian Jira is succesvol ontkoppeld.'));
+            exit;
         }
     }
 
-    // 2. Outlook Opslaan
+    // 2. Outlook Opslaan of Koppelen
     elseif ($provider === 'OUTLOOK') {
         $clientId = trim($_POST['client_id'] ?? '');
         $clientSecret = trim($_POST['client_secret'] ?? '');
         $tenantId = trim($_POST['tenant_id'] ?? 'common');
+        if (empty($tenantId)) $tenantId = 'common';
         $isDemo = isset($_POST['is_demo_mode']) ? 1 : 0;
 
         // Haal bestaande tokens op
@@ -71,12 +75,22 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
                 last_sync_at = NOW()
         ");
         $stmt->execute([$userId, $isDemo, json_encode($newSettings)]);
-        $message = "Instellingen voor Microsoft Outlook zijn opgeslagen.";
 
         // Als gebruiker direct op 'Koppel nu' klikte
         if ($action === 'connect_oauth') {
-            header("Location: /auth/oauth_microsoft.php?client_id=" . urlencode($clientId) . "&tenant_id=" . urlencode($tenantId));
-            exit;
+            if (empty($clientId)) {
+                $message = "Vul eerst de Application (Client) ID in van uw Azure App Registratie.";
+                $messageType = 'error';
+            } elseif (empty($clientSecret)) {
+                $message = "Vul eerst het Client Secret in van uw Azure App Registratie.";
+                $messageType = 'error';
+            } else {
+                header("Location: /auth/oauth_microsoft.php?client_id=" . urlencode($clientId) . "&tenant_id=" . urlencode($tenantId));
+                exit;
+            }
+        } else {
+            $message = "Instellingen voor Microsoft Outlook zijn succesvol opgeslagen.";
+            $messageType = 'success';
         }
     }
 
@@ -121,9 +135,11 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
                 $accountName = $testRes['user']['displayName'] ?? 'Jira Gebruiker';
                 $accountId = $testRes['user']['accountId'] ?? '';
                 $message = "Verbinding met Jira geslaagd! Ingelogd als: {$accountName}";
+                $messageType = 'success';
             }
         } else {
             $message = "Jira instellingen opgeslagen.";
+            $messageType = 'success';
         }
 
         $newSettings = [
@@ -149,6 +165,9 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
     }
 }
 
+// Laad nu pas de HTML header in
+require_once __DIR__ . '/includes/header.php';
+
 // Haal huidige configuraties op
 $stmtConfigs = $db->prepare("SELECT * FROM integrations WHERE user_id = ?");
 $stmtConfigs->execute([$userId]);
@@ -300,42 +319,59 @@ $redirectUri = rtrim(APP_URL, '/') . '/auth/callback_microsoft.php';
                 <input type="hidden" name="provider" value="OUTLOOK">
 
                 <div>
-                    <label class="block text-[10px] font-semibold text-slate-400 mb-0.5">Application (Client) ID</label>
+                    <label class="block text-[10px] font-semibold text-slate-400 mb-0.5">
+                        Application (Client) ID <span class="text-blue-400">*</span>
+                    </label>
                     <input 
                         type="text" 
                         name="client_id" 
                         value="<?= htmlspecialchars($outlookSettings['client_id'] ?? fociz_env('MICROSOFT_CLIENT_ID', '')) ?>"
-                        placeholder="e.g. 11111111-2222-3333-4444-555555555555" 
+                        placeholder="bijv. e8f498c1-1234-4567-89ab-cdef01234567" 
                         class="w-full bg-slate-950 border border-slate-800 rounded-lg px-2.5 py-1.5 text-xs text-white placeholder-slate-600 focus:outline-none focus:border-blue-500 font-mono"
                     >
+                    <p class="text-[10px] text-slate-500 mt-0.5">Te vinden op de Overzichtspagina (Overview) van uw Azure App Registratie.</p>
                 </div>
 
                 <div>
-                    <label class="block text-[10px] font-semibold text-slate-400 mb-0.5">Client Secret</label>
+                    <label class="block text-[10px] font-semibold text-slate-400 mb-0.5">
+                        Client Secret (Geheim) <span class="text-blue-400">*</span>
+                    </label>
                     <div class="relative">
                         <input 
                             type="password" 
                             id="msClientSecret"
                             name="client_secret" 
                             value="<?= !empty($outlookSettings['client_secret']) ? '••••••••••••••••' : htmlspecialchars(fociz_env('MICROSOFT_CLIENT_SECRET', '')) ?>"
-                            placeholder="Client Secret Value" 
+                            placeholder="Plak hier de Waarde (Value) van uw Client Secret" 
                             class="w-full bg-slate-950 border border-slate-800 rounded-lg px-2.5 py-1.5 pr-8 text-xs text-white placeholder-slate-600 focus:outline-none focus:border-blue-500 font-mono"
                         >
                         <button type="button" onclick="togglePasswordVisibility('msClientSecret')" class="absolute right-2 top-2 text-slate-500 hover:text-slate-300">
                             <i data-lucide="eye" class="w-3.5 h-3.5"></i>
                         </button>
                     </div>
+                    <p class="text-[10px] text-slate-500 mt-0.5">Aangemaakt onder <em>Certificaten en geheimen &gt; Nieuw clientgeheim</em> (kopieer de <strong>Waarde / Value</strong>).</p>
                 </div>
 
                 <div>
-                    <label class="block text-[10px] font-semibold text-slate-400 mb-0.5">Directory (Tenant) ID</label>
+                    <div class="flex items-center justify-between mb-0.5">
+                        <label class="text-[10px] font-semibold text-slate-400">Directory (Tenant) ID</label>
+                        <span class="text-[9px] text-blue-400 font-semibold bg-blue-500/10 px-1.5 py-0.5 rounded">Standaard: common</span>
+                    </div>
                     <input 
                         type="text" 
                         name="tenant_id" 
-                        value="<?= htmlspecialchars($outlookSettings['tenant_id'] ?? fociz_env('MICROSOFT_TENANT_ID', 'common')) ?>"
-                        placeholder="common of specifiek GUID" 
+                        value="<?= htmlspecialchars(!empty($outlookSettings['tenant_id']) ? $outlookSettings['tenant_id'] : 'common') ?>"
+                        placeholder="common of organizations" 
                         class="w-full bg-slate-950 border border-slate-800 rounded-lg px-2.5 py-1.5 text-xs text-white placeholder-slate-600 focus:outline-none focus:border-blue-500 font-mono"
                     >
+                    <div class="text-[10px] text-slate-400 mt-1.5 leading-relaxed bg-slate-950/80 p-2.5 rounded-lg border border-slate-800/80 space-y-1">
+                        <p class="font-semibold text-slate-300 flex items-center space-x-1">
+                            <span>💡 Wat moet hier staan?</span>
+                        </p>
+                        <p>• Laat simpelweg <code>common</code> staan (werkt voor elk Microsoft account).</p>
+                        <p>• Of vul <code>organizations</code> in voor elk zakelijk Microsoft 365 werkaccount.</p>
+                        <p>• U hoeft alleen uw specifieke Tenant GUID in te vullen als uw Azure app is ingesteld op <em>Single tenant (Alleen mijn eigen organisatie)</em>.</p>
+                    </div>
                 </div>
 
                 <label class="flex items-center space-x-2 text-xs text-slate-300 pt-1">