diff --git a/src/Controller/Admin/EFlexController.php b/src/Controller/Admin/EFlexController.php
index 35daab5..af0203f 100644
--- a/src/Controller/Admin/EFlexController.php
+++ b/src/Controller/Admin/EFlexController.php
@@ -39,6 +39,21 @@ class EFlexController extends AbstractController
             throw $this->createNotFoundException('Client introuvable');
         }
 
+        // Bloquer si un E-Flex est en cours ou annule (defaut)
+        $existingEflex = $this->em->getRepository(EFlex::class)->findBy(['customer' => $customer]);
+        foreach ($existingEflex as $existing) {
+            if (\in_array($existing->getState(), [EFlex::STATE_ACTIVE, EFlex::STATE_PENDING_SETUP, EFlex::STATE_DRAFT], true)) {
+                $this->addFlash('error', 'Un E-Flex est deja en cours ('.$existing->getReference().'). Impossible d\'en creer un nouveau.');
+
+                return $this->redirectToRoute('app_admin_clients_show', ['id' => $customerId, 'tab' => 'esyflex']);
+            }
+            if (EFlex::STATE_CANCELLED === $existing->getState() && $existing->getNbFailed() > 0) {
+                $this->addFlash('error', 'Un E-Flex est en defaut ('.$existing->getReference().'). Le client doit regulariser avant de creer un nouveau E-Flex.');
+
+                return $this->redirectToRoute('app_admin_clients_show', ['id' => $customerId, 'tab' => 'esyflex']);
+            }
+        }
+
         $description = trim($request->request->getString('description'));
         $totalAmount = $request->request->getString('totalAmount');
         $nbEcheances = $request->request->getInt('nbEcheances');
diff --git a/src/Controller/WebhookStripeController.php b/src/Controller/WebhookStripeController.php
index f46d989..6448f7b 100644
--- a/src/Controller/WebhookStripeController.php
+++ b/src/Controller/WebhookStripeController.php
@@ -761,12 +761,52 @@ class WebhookStripeController extends AbstractController
         $line->setStripePaymentIntentId($paymentIntent->id);
         $this->em->flush();
 
+        $cancelled = false;
         if ($eflex->getNbFailed() >= 2) {
             $eflex->setState(\App\Entity\EFlex::STATE_CANCELLED);
             $this->em->flush();
+            $cancelled = true;
         }
 
         $customer = $eflex->getCustomer();
+
+        // Si annule : envoyer mail d'annulation au client + admin
+        if ($cancelled) {
+            if (null !== $customer->getEmail()) {
+                try {
+                    $this->mailer->sendEmail(
+                        $customer->getEmail(),
+                        'E-Flex '.$eflex->getReference().' annule - Rejets de prelevement',
+                        $this->twig->render('emails/eflex_cancelled.html.twig', [
+                            'customer' => $customer,
+                            'eflex' => $eflex,
+                        ]),
+                        null,
+                        null,
+                        false,
+                    );
+                } catch (\Throwable) {
+                    // silencieux
+                }
+            }
+
+            try {
+                $this->mailer->sendEmail(
+                    self::NOTIFICATION_EMAIL,
+                    'E-Flex '.$eflex->getReference().' annule (2 rejets) - '.$customer->getFullName(),
+                    $this->twig->render('emails/eflex_cancelled.html.twig', [
+                        'customer' => $customer,
+                        'eflex' => $eflex,
+                    ]),
+                    null,
+                    null,
+                    false,
+                );
+            } catch (\Throwable) {
+                // silencieux
+            }
+        }
+
         if (null !== $customer->getEmail()) {
             try {
                 $payUrl = $this->urlGenerator->generate('app_eflex_pay', [
diff --git a/templates/admin/clients/show.html.twig b/templates/admin/clients/show.html.twig
index 81a5f88..cdc4e13 100644
--- a/templates/admin/clients/show.html.twig
+++ b/templates/admin/clients/show.html.twig
@@ -1208,9 +1208,26 @@
 
     {# Tab: E-Flex #}
     {% elseif tab == 'esyflex' %}
+        {% set hasActiveEflex = false %}
+        {% set hasDefaultEflex = false %}
+        {% for e in eflexList %}
+            {% if e.state in ['active', 'pending_setup', 'draft'] %}
+                {% set hasActiveEflex = true %}
+            {% endif %}
+            {% if e.state == 'cancelled' and e.nbFailed > 0 %}
+                {% set hasDefaultEflex = true %}
+            {% endif %}
+        {% endfor %}
+
         <div class="flex items-center justify-between mb-4">
             <h2 class="text-lg font-bold uppercase">E-Flex</h2>
-            <button type="button" data-modal-open="modal-eflex" class="btn-gold px-4 py-2 font-bold uppercase text-[10px] tracking-wider text-gray-900">Creer un E-Flex</button>
+            {% if hasDefaultEflex %}
+                <span class="px-4 py-2 bg-red-500/20 text-red-700 font-bold uppercase text-[10px] tracking-wider cursor-not-allowed" title="E-Flex en defaut - regularisation necessaire">Creation bloquee (defaut)</span>
+            {% elseif hasActiveEflex %}
+                <span class="px-4 py-2 bg-yellow-500/20 text-yellow-700 font-bold uppercase text-[10px] tracking-wider cursor-not-allowed" title="Un E-Flex est deja en cours">E-Flex en cours</span>
+            {% else %}
+                <button type="button" data-modal-open="modal-eflex" class="btn-gold px-4 py-2 font-bold uppercase text-[10px] tracking-wider text-gray-900">Creer un E-Flex</button>
+            {% endif %}
         </div>
 
         {% if eflexList|length > 0 %}
diff --git a/templates/emails/eflex_cancelled.html.twig b/templates/emails/eflex_cancelled.html.twig
new file mode 100644
index 0000000..e370200
--- /dev/null
+++ b/templates/emails/eflex_cancelled.html.twig
@@ -0,0 +1,57 @@
+{% extends 'email/base.html.twig' %}
+
+{% block content %}
+<table width="600" cellpadding="0" cellspacing="0" style="margin: 0 auto;">
+    <tr>
+        <td style="padding: 32px;">
+            {% set greeting = customer.raisonSociale ? 'Chez ' ~ customer.raisonSociale : 'Bonjour ' ~ customer.firstName %}
+            <h1 style="font-family: Arial, Helvetica, sans-serif; font-size: 22px; font-weight: 700; color: #111827; margin: 0 0 16px;">{{ greeting }},</h1>
+
+            <div style="background: #fef2f2; border-left: 4px solid #dc2626; padding: 16px; margin: 0 0 20px;">
+                <p style="font-family: Arial, Helvetica, sans-serif; font-size: 14px; font-weight: 700; color: #dc2626; margin: 0;">
+                    E-Flex {{ eflex.reference }} annule
+                </p>
+            </div>
+
+            <p style="font-family: Arial, Helvetica, sans-serif; font-size: 14px; color: #374151; line-height: 22px; margin: 0 0 16px;">
+                Votre contrat de financement E-Flex a ete automatiquement annule suite a des rejets repetes de prelevement. Le solde restant reste du.
+            </p>
+
+            <table width="100%" cellpadding="0" cellspacing="0" style="margin: 20px 0; border: 1px solid #e5e7eb;">
+                <tr>
+                    <td style="padding: 10px 16px; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: #9ca3af; background: #f9fafb; width: 35%;">Reference</td>
+                    <td style="padding: 10px 16px; font-family: monospace; font-size: 13px; font-weight: 700;">{{ eflex.reference }}</td>
+                </tr>
+                <tr>
+                    <td style="padding: 10px 16px; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: #9ca3af; background: #f9fafb;">Total contrat</td>
+                    <td style="padding: 10px 16px; font-family: monospace; font-size: 14px; font-weight: 700;">{{ eflex.totalAmount|number_format(2, ',', ' ') }} &euro;</td>
+                </tr>
+                <tr>
+                    <td style="padding: 10px 16px; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: #9ca3af; background: #f9fafb;">Deja paye</td>
+                    <td style="padding: 10px 16px; font-family: monospace; font-size: 14px; font-weight: 700; color: #16a34a;">{{ eflex.totalPaid|number_format(2, ',', ' ') }} &euro;</td>
+                </tr>
+                <tr>
+                    <td style="padding: 10px 16px; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: #9ca3af; background: #f9fafb;">Restant du</td>
+                    <td style="padding: 10px 16px; font-family: monospace; font-size: 16px; font-weight: 700; color: #dc2626;">{{ (eflex.totalAmount|number_format(2, '.', '') - eflex.totalPaid)|number_format(2, ',', ' ') }} &euro;</td>
+                </tr>
+                <tr>
+                    <td style="padding: 10px 16px; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: #9ca3af; background: #f9fafb;">Echeances payees</td>
+                    <td style="padding: 10px 16px; font-size: 13px;">{{ eflex.nbPaid }}/{{ eflex.nbLines }}</td>
+                </tr>
+                <tr>
+                    <td style="padding: 10px 16px; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 1px; color: #9ca3af; background: #f9fafb;">Rejets</td>
+                    <td style="padding: 10px 16px; font-size: 13px; font-weight: 700; color: #dc2626;">{{ eflex.nbFailed }} echec(s)</td>
+                </tr>
+            </table>
+
+            <p style="font-family: Arial, Helvetica, sans-serif; font-size: 14px; color: #374151; line-height: 22px; margin: 16px 0;">
+                Veuillez contacter notre service pour regulariser votre situation dans les plus brefs delais.
+            </p>
+
+            <p style="font-family: Arial, Helvetica, sans-serif; font-size: 12px; color: #9ca3af; margin: 16px 0 0;">
+                Pour toute question : <a href="mailto:contact@e-cosplay.fr" style="color: #fabf04;">contact@e-cosplay.fr</a>
+            </p>
+        </td>
+    </tr>
+</table>
+{% endblock %}