diff --git a/core/templates/core/base/notifications.jinja b/core/templates/core/base/notifications.jinja
index 6eb7b749..fd365391 100644
--- a/core/templates/core/base/notifications.jinja
+++ b/core/templates/core/base/notifications.jinja
@@ -10,7 +10,7 @@
   <template x-for="(message, index) in $notifications.getAll()">
     <div class="alert" :class="`alert-${message.tag}`" x-transition>
       <span class="alert-main" x-text="message.text"></span>
-      <span class="clickable" @click="messages = messages.filter((item, i) => i !== index)">
+      <span class="clickable" @click="$store.notifications = $store.notifications.filter((item, i) => i !== index)">
         <i class="fa fa-close"></i>
       </span>
     </div>
diff --git a/eboutic/api.py b/eboutic/api.py
index c44a8cc9..f1c6ccc2 100644
--- a/eboutic/api.py
+++ b/eboutic/api.py
@@ -1,3 +1,6 @@
+from typing import Any
+
+from ninja import Status
 from ninja_extra import ControllerBase, api_controller, route
 from ninja_extra.exceptions import NotFound
 
@@ -8,13 +11,19 @@ from eboutic.models import Basket
 
 @api_controller("/etransaction", permissions=[CanView])
 class EtransactionInfoController(ControllerBase):
-    @route.get("/data/{basket_id}", url_name="etransaction_data")
+    @route.get(
+        "/data/{basket_id}",
+        url_name="etransaction_data",
+        response={200: dict[str, Any], 410: str},
+    )
     def fetch_etransaction_data(self, basket_id: int):
         """Generate the data to pay an eboutic command with paybox.
 
         The data is generated with the basket that is used by the current session.
         """
         basket: Basket = self.get_object_or_exception(Basket, pk=basket_id)
+        if basket.is_expired:
+            return Status(410, "This basket is expired.")
         try:
             return dict(basket.get_e_transaction_data())
         except BillingInfo.DoesNotExist as e:
diff --git a/eboutic/models.py b/eboutic/models.py
index cf6e15ab..af029ae1 100644
--- a/eboutic/models.py
+++ b/eboutic/models.py
@@ -24,6 +24,7 @@ from django.conf import settings
 from django.db import DataError, models
 from django.db.models import F, OuterRef, Subquery, Sum
 from django.utils.functional import cached_property
+from django.utils.timezone import now
 from django.utils.translation import gettext_lazy as _
 
 from core.models import User
@@ -95,6 +96,10 @@ class Basket(models.Model):
             ]
         )
 
+    @property
+    def is_expired(self) -> bool:
+        return (self.date + settings.SITH_EBOUTIC_BASKET_TIMEOUT) <= now()
+
     def generate_sales(
         self, counter, seller: User, payment_method: Selling.PaymentMethod
     ):
@@ -133,9 +138,20 @@ class Basket(models.Model):
         ]
 
     def get_e_transaction_data(self) -> list[tuple[str, str]]:
+        """Get data for etransaction payment.
+
+        Raises:
+            Customer.DoesNotExist: if the user linked to this basket
+                has no customer account
+            BillingInfo.DoesNotExist: if the user linked to this basket has no
+                billing infos, or incorrect billing infos.
+            ValueError: if this is called on a basket which payment delay is expired.
+        """
         user = self.user
         if not hasattr(user, "customer"):
             raise Customer.DoesNotExist
+        if self.is_expired:
+            raise ValueError("This method cannot be called on an expired basket.")
         customer = user.customer
         if (
             not hasattr(user.customer, "billing_infos")
@@ -155,6 +171,10 @@ class Basket(models.Model):
             ("PBX_IDENTIFIANT", settings.SITH_EBOUTIC_PBX_IDENTIFIANT),
             ("PBX_TOTAL", str(int(self.total * 100))),
             ("PBX_DEVISE", "978"),  # This is Euro
+            (
+                "PBX_DISPLAY",
+                str(int(settings.SITH_EBOUTIC_ETRANSACTION_TIMEOUT.total_seconds())),
+            ),
             ("PBX_CMD", str(self.id)),
             ("PBX_PORTEUR", user.email),
             ("PBX_RETOUR", "Amount:M;BasketID:R;Auto:A;Error:E;Sig:K"),
diff --git a/eboutic/static/bundled/eboutic/checkout-index.ts b/eboutic/static/bundled/eboutic/checkout-index.ts
index cb4be7f0..08683218 100644
--- a/eboutic/static/bundled/eboutic/checkout-index.ts
+++ b/eboutic/static/bundled/eboutic/checkout-index.ts
@@ -1,21 +1,71 @@
+import { type Notification, NotificationLevel } from "#core:utils/notifications";
 import { etransactioninfoFetchEtransactionData } from "#openapi";
 
+interface Basket {
+  id: number;
+  timeout: Date;
+}
 document.addEventListener("alpine:init", () => {
-  Alpine.data("etransaction", (initialData, basketId: number) => ({
+  Alpine.data("etransaction", (initialData, basket: Basket) => ({
     data: initialData,
     isCbAvailable: Object.keys(initialData).length > 0,
+    isSithAvailable: true,
 
+    init() {
+      const now = new Date();
+      const timeout = basket.timeout.getTime() - now.getTime();
+      if (timeout <= 0) {
+        // basket was already outdated at initial page load
+        this.timeoutBasket();
+      } else {
+        setTimeout(() => this.timeoutBasket(), timeout);
+      }
+    },
+
+    /**
+     * Make this basket into a timeout state.
+     * All submission inputs are disabled, and an error message is displayed.
+     */
+    timeoutBasket() {
+      this.isCbAvailable = false;
+      this.isSithAvailable = false;
+      const message = gettext("Basket expired");
+
+      const existingNotif: Notification | undefined = this.$notifications
+        .getAll()
+        .find(
+          (n: Notification) =>
+            n.tag === NotificationLevel.Error && n.message === message,
+        );
+      if (existingNotif === undefined) {
+        this.$notifications.error(message);
+      }
+    },
+
+    /**
+     * Refresh the data used for etransaction.
+     *
+     * Note: if this is called while the basket is expired, it will be a no-op
+     */
     async fill() {
+      if (new Date() > basket.timeout) {
+        // refresh etransaction data only if the basket is still valid.
+        this.timeoutBasket();
+        return;
+      }
       this.isCbAvailable = false;
       const res = await etransactioninfoFetchEtransactionData({
-        path: {
-          // biome-ignore lint/style/useNamingConvention: api is in snake_case
-          basket_id: basketId,
-        },
+        // biome-ignore lint/style/useNamingConvention: api is in snake_case
+        path: { basket_id: basket.id },
       });
       if (res.response.ok) {
         this.data = res.data;
         this.isCbAvailable = true;
+      } else if (res.response.status === 410) {
+        // The basket is expired, so no payment method should be available at all.
+        // This shouldn't happen, because we don't send the request
+        // when the timeout is passed, but we are better safe than sorry
+        this.timeoutBasket();
       }
     },
   }));
diff --git a/eboutic/templates/eboutic/eboutic_billing_info.jinja b/eboutic/templates/eboutic/eboutic_billing_info.jinja
index 57ea97ed..df8152ef 100644
--- a/eboutic/templates/eboutic/eboutic_billing_info.jinja
+++ b/eboutic/templates/eboutic/eboutic_billing_info.jinja
@@ -21,6 +21,7 @@
       hx-swap="outerHTML"
       hx-target="#billing-infos-fragment"
       x-show="collapsed"
+      x-cloak
     >
       {% csrf_token %}
       {{ form.as_p() }}
diff --git a/eboutic/templates/eboutic/eboutic_checkout.jinja b/eboutic/templates/eboutic/eboutic_checkout.jinja
index 369c5d44..59a490ce 100644
--- a/eboutic/templates/eboutic/eboutic_checkout.jinja
+++ b/eboutic/templates/eboutic/eboutic_checkout.jinja
@@ -15,11 +15,10 @@
 {% block content %}
   <h3>{% trans %}Eboutic{% endtrans %}</h3>
 
-  <script type="text/javascript">
-    let billingInfos = {{ billing_infos|safe }};
-  </script>
-
-  <div x-data="etransaction(billingInfos, {{ basket.id }})">
+  <div x-data='etransaction(
+               {{ billing_infos|tojson }},
+               { id: {{ basket.id }}, timeout: new Date("{{ basket.date + settings.SITH_EBOUTIC_BASKET_TIMEOUT }}") }
+               )'>
     <p>{% trans %}Basket: {% endtrans %}</p>
     <table>
       <thead>
@@ -72,7 +71,11 @@
           x-cloak
           type="submit"
           id="bank-submit-button"
-          :disabled="!isCbAvailable"
+          {% if basket.is_expired %}
+            disabled="disabled"
+          {% else %}
+            :disabled="!isCbAvailable"
+          {% endif %}
           class="btn btn-blue"
           value="{% trans %}Pay with credit card{% endtrans %}"
         />
@@ -93,7 +96,16 @@
     {% else %}
       <form method="post" action="{{ url('eboutic:pay_with_sith', basket_id=basket.id) }}" name="sith-pay-form">
         {% csrf_token %}
-        <input class="btn btn-blue" type="submit" value="{% trans %}Pay with Sith account{% endtrans %}"/>
+        <input
+          {% if basket.is_expired %}
+            disabled="disabled"
+          {% else %}
+            :disabled="!isSithAvailable"
+          {% endif %}
+          class="btn btn-blue"
+          type="submit"
+          value="{% trans %}Pay with Sith account{% endtrans %}"
+        />
       </form>
     {% endif %}
   </div>
diff --git a/eboutic/tests/test_payment.py b/eboutic/tests/test_payment.py
index 5c4b1da1..0a568015 100644
--- a/eboutic/tests/test_payment.py
+++ b/eboutic/tests/test_payment.py
@@ -3,6 +3,7 @@ import urllib
 from decimal import Decimal
 from typing import TYPE_CHECKING
 
+import freezegun
 from cryptography.hazmat.primitives.asymmetric.padding import PKCS1v15
 from cryptography.hazmat.primitives.asymmetric.rsa import RSAPrivateKey
 from cryptography.hazmat.primitives.hashes import SHA1
@@ -105,7 +106,7 @@ class TestPaymentSith(TestPaymentBase):
             ),
             reverse("eboutic:payment_result", kwargs={"result": "success"}),
         )
-        assert Basket.objects.filter(id=self.basket.id).first() is None
+        assert not Basket.objects.filter(id=self.basket.id).exists()
         self.customer.customer.refresh_from_db()
         assert self.customer.customer.amount == Decimal(1)
 
@@ -139,10 +140,7 @@ class TestPaymentSith(TestPaymentBase):
         assert len(messages) == 1
         assert messages[0].level == DEFAULT_LEVELS["ERROR"]
         assert messages[0].message == "Solde insuffisant"
-
-        assert Basket.objects.contains(self.basket), (
-            "After an unsuccessful request, the basket should be kept"
-        )
+        assert not Basket.objects.filter(id=self.basket.id).exists()
 
     def test_refilling_in_basket(self):
         BasketItem.from_price(self.refilling.prices.first(), 1, self.basket).save()
@@ -157,7 +155,7 @@ class TestPaymentSith(TestPaymentBase):
             response,
             reverse("eboutic:payment_result", kwargs={"result": "failure"}),
         )
-        assert Basket.objects.filter(id=self.basket.id).first() is not None
+        assert not Basket.objects.filter(id=self.basket.id).exists()
         messages = list(get_messages(response.wsgi_request))
         assert messages[0].level == DEFAULT_LEVELS["ERROR"]
         assert (
@@ -167,6 +165,24 @@ class TestPaymentSith(TestPaymentBase):
         self.customer.customer.refresh_from_db()
         assert self.customer.customer.amount == initial_account_balance
 
+    def test_basket_expired(self):
+        self.client.force_login(self.customer)
+        initial_account_balance = self.customer.customer.amount
+        with freezegun.freeze_time(settings.SITH_EBOUTIC_BASKET_TIMEOUT):
+            response = self.client.post(
+                reverse("eboutic:pay_with_sith", kwargs={"basket_id": self.basket.id})
+            )
+        assertRedirects(
+            response,
+            reverse("eboutic:payment_result", kwargs={"result": "failure"}),
+        )
+        messages = list(get_messages(response.wsgi_request))
+        assert messages[0].level == DEFAULT_LEVELS["ERROR"]
+        assert messages[0].message == "Panier expiré"
+        assert not Basket.objects.filter(id=self.basket.id).exists()
+        self.customer.customer.refresh_from_db()
+        assert self.customer.customer.amount == initial_account_balance
+
 
 class TestPaymentCard(TestPaymentBase):
     def generate_bank_valid_answer(self, basket: Basket):
diff --git a/eboutic/views.py b/eboutic/views.py
index 82704be3..c892a104 100644
--- a/eboutic/views.py
+++ b/eboutic/views.py
@@ -39,6 +39,8 @@ from django.db.utils import cached_property
 from django.http import HttpResponse
 from django.shortcuts import redirect, render
 from django.urls import reverse
+from django.utils.formats import localize
+from django.utils.timezone import localtime
 from django.utils.translation import gettext_lazy as _
 from django.views.decorators.http import require_GET
 from django.views.generic import DetailView, FormView, TemplateView, UpdateView, View
@@ -187,9 +189,7 @@ class BillingInfoFormFragment(
 
     def get_initial(self):
         if self.object is None:
-            return {
-                "country": Country(code="FR"),
-            }
+            return {"country": Country(code="FR")}
         return {}
 
     def render_fragment(self, request, **kwargs) -> SafeString:
@@ -255,10 +255,19 @@ class EbouticCheckout(CanViewMixin, UseFragmentsMixin, DetailView):
             kwargs["customer_amount"] = None
         kwargs["billing_infos"] = {}
 
-        with contextlib.suppress(BillingInfo.DoesNotExist):
-            kwargs["billing_infos"] = json.dumps(
-                dict(self.object.get_e_transaction_data())
+        if self.object.is_expired:
+            messages.error(self.request, _("Basket expired"))
+        else:
+            timeout = self.object.date + settings.SITH_EBOUTIC_BASKET_TIMEOUT
+            messages.warning(
+                self.request,
+                _("Basket available until %(until)s")
+                % {"until": localize(localtime(timeout).time())},
             )
+            with contextlib.suppress(BillingInfo.DoesNotExist):
+                kwargs["billing_infos"] = json.dumps(
+                    dict(self.object.get_e_transaction_data())
+                )
         return kwargs
 
 
@@ -268,9 +277,14 @@ class EbouticPayWithSith(CanViewMixin, SingleObjectMixin, View):
 
     def post(self, request, *args, **kwargs):
         basket = self.get_object()
+        if basket.is_expired:
+            messages.error(self.request, _("Basket expired"))
+            basket.delete()
+            return redirect("eboutic:payment_result", "failure")
         refilling = settings.SITH_COUNTER_PRODUCTTYPE_REFILLING
         if basket.items.filter(product__product_type_id=refilling).exists():
             messages.error(self.request, _("You can't buy a refilling with sith money"))
+            basket.delete()
             return redirect("eboutic:payment_result", "failure")
 
         eboutic = get_eboutic()
@@ -288,6 +302,7 @@ class EbouticPayWithSith(CanViewMixin, SingleObjectMixin, View):
         except DatabaseError as e:
             sentry_sdk.capture_exception(e)
         except ValidationError as e:
+            basket.delete()
             messages.error(self.request, e.message)
         return redirect("eboutic:payment_result", "failure")
 
diff --git a/locale/fr/LC_MESSAGES/django.po b/locale/fr/LC_MESSAGES/django.po
index 28f562b1..0c390058 100644
--- a/locale/fr/LC_MESSAGES/django.po
+++ b/locale/fr/LC_MESSAGES/django.po
@@ -6,7 +6,7 @@
 msgid ""
 msgstr ""
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2026-05-12 11:12+0200\n"
+"POT-Creation-Date: 2026-05-15 11:46+0200\n"
 "PO-Revision-Date: 2016-07-18\n"
 "Last-Translator: Maréchal <thomas.girod@utbm.fr\n"
 "Language-Team: AE info <ae.info@utbm.fr>\n"
@@ -4505,6 +4505,15 @@ msgstr ""
 "souhaitez payer par carte, vous devez rajouter un numéro de téléphone aux "
 "données que vous aviez déjà fourni."
 
+#: eboutic/views.py
+msgid "Basket expired"
+msgstr "Panier expiré"
+
+#: eboutic/views.py
+#, python-format
+msgid "Basket available until %(until)s"
+msgstr "Panier disponible jusqu'à %(until)s"
+
 #: eboutic/views.py
 msgid "You can't buy a refilling with sith money"
 msgstr "Vous ne pouvez pas acheter un rechargement avec de l'argent du sith"
diff --git a/locale/fr/LC_MESSAGES/djangojs.po b/locale/fr/LC_MESSAGES/djangojs.po
index 78e15202..33d24897 100644
--- a/locale/fr/LC_MESSAGES/djangojs.po
+++ b/locale/fr/LC_MESSAGES/djangojs.po
@@ -7,7 +7,7 @@
 msgid ""
 msgstr ""
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2026-04-17 22:42+0200\n"
+"POT-Creation-Date: 2026-05-17 10:03+0200\n"
 "PO-Revision-Date: 2024-09-17 11:54+0200\n"
 "Last-Translator: Sli <antoine@bartuccio.fr>\n"
 "Language-Team: AE info <ae.info@utbm.fr>\n"
@@ -263,6 +263,10 @@ msgstr "Types de produits réordonnés !"
 msgid "Product type reorganisation failed with status code : %d"
 msgstr "La réorganisation des types de produit a échoué avec le code : %d"
 
+#: eboutic/static/bundled/eboutic/checkout-index.ts
+msgid "Basket expired"
+msgstr "Panier expiré"
+
 #: sas/static/bundled/sas/pictures-download-index.ts
 msgid "pictures.%(extension)s"
 msgstr "photos.%(extension)s"
diff --git a/sith/settings.py b/sith/settings.py
index 9968055f..bf89dbda 100644
--- a/sith/settings.py
+++ b/sith/settings.py
@@ -571,6 +571,11 @@ SITH_BARMAN_TIMEOUT = 30
 # Minutes to delete the last operations
 SITH_LAST_OPERATIONS_LIMIT = 10
 
+# time before a basket is considered expired
+SITH_EBOUTIC_BASKET_TIMEOUT = timedelta(minutes=10)
+# time that a user can spend on the CB payment page before it to timeout
+SITH_EBOUTIC_ETRANSACTION_TIMEOUT = timedelta(minutes=10)
+
 # ET variables
 SITH_EBOUTIC_CB_ENABLED = env.bool("SITH_EBOUTIC_CB_ENABLED", default=True)
 SITH_EBOUTIC_ET_URL = env.str(