diff --git a/la_chariotte/order/models.py b/la_chariotte/order/models.py
index 70bc93b..7329c72 100644
--- a/la_chariotte/order/models.py
+++ b/la_chariotte/order/models.py
@@ -137,7 +137,7 @@ class Item(models.Model):
 
     def get_remaining_nb(self):
         """Returns the number of remaining articles for this item in this grouped order"""
-        if self.max_limit:
+        if self.max_limit is not None:
             return self.max_limit - self.ordered_nb
         else:
             return None
diff --git a/la_chariotte/order/templates/order/grouped_order_detail.html b/la_chariotte/order/templates/order/grouped_order_detail.html
index f2366d2..e9fb726 100644
--- a/la_chariotte/order/templates/order/grouped_order_detail.html
+++ b/la_chariotte/order/templates/order/grouped_order_detail.html
@@ -65,7 +65,7 @@
           <td>{{ item.name }}</td>
           <td>{{ item.price }} €</td>
           <td><input name="quantity_{{ item.id }}" size="2" type="number" value="0" min="0"></input>
-            {% if item.get_remaining_nb %}<span class="is-italic"> {{ item.get_remaining_nb }} disponibles</span>{% endif %}</td>
+            {% if item.get_remaining_nb is not null %}<span class="is-italic"> {{ item.get_remaining_nb }} {% if item.get_remaining_nb <= 1 %}disponible{% else %}disponibles{% endif %}</span>{% endif %}</td>
         </tr>
         {% endfor %}
       </tbody>
diff --git a/la_chariotte/order/tests/test_views.py b/la_chariotte/order/tests/test_views.py
index 643b718..fb0a01f 100644
--- a/la_chariotte/order/tests/test_views.py
+++ b/la_chariotte/order/tests/test_views.py
@@ -395,6 +395,153 @@ class TestGroupedOrderDetailView:
         assert "gr order test" in response.content.decode()
         assert "Cette commande groupée est terminée" in response.content.decode()
 
+    def test_order_too_many_items(self, client, other_user):
+        """a user orders more items than what is available. They get an error"""
+        grouped_order = create_grouped_order(
+            days_before_delivery_date=5,
+            days_before_deadline=2,
+            name="gr order test",
+            orga_user=other_user,
+        )
+        item = models.Item.objects.create(
+            name="test item 1", grouped_order=grouped_order, price=1, max_limit=1
+        )
+        detail_url = reverse(
+            "order:grouped_order_detail",
+            kwargs={
+                "pk": grouped_order.pk,
+            },
+        )
+        response = client.get(detail_url)
+        assert response.status_code == 200
+        assert "test item" in response.content.decode()
+        assert "gr order test" in response.content.decode()
+        assert item.ordered_nb == 0
+        order_url = reverse(
+            "order:order",
+            kwargs={
+                "grouped_order_id": grouped_order.pk,
+            },
+        )
+        response = client.post(
+            order_url,
+            {
+                f"quantity_{item.pk}": 2,
+                "first_name": "Prénom",
+                "last_name": "Nom",
+                "phone": "0645632569",
+                "email": "test@mail.fr",
+            },
+        )
+        assert response.status_code == 200
+        assert (
+            response.context["error_message"]
+            == "Trop de test item 1 commandés pour la quantité disponible"
+        )
+        assert not models.Order.objects.first()
+        assert not models.OrderAuthor.objects.first()
+
+    def test_order_no_item_available(self, client, other_user):
+        """a user an item that is not available. They get an error"""
+        grouped_order = create_grouped_order(
+            days_before_delivery_date=5,
+            days_before_deadline=2,
+            name="gr order test",
+            orga_user=other_user,
+        )
+        item = models.Item.objects.create(
+            name="test item 1", grouped_order=grouped_order, price=1, max_limit=0
+        )
+        detail_url = reverse(
+            "order:grouped_order_detail",
+            kwargs={
+                "pk": grouped_order.pk,
+            },
+        )
+        response = client.get(detail_url)
+        assert response.status_code == 200
+        assert "test item" in response.content.decode()
+        assert "gr order test" in response.content.decode()
+        assert item.ordered_nb == 0
+        order_url = reverse(
+            "order:order",
+            kwargs={
+                "grouped_order_id": grouped_order.pk,
+            },
+        )
+        response = client.post(
+            order_url,
+            {
+                f"quantity_{item.pk}": 1,
+                "first_name": "Prénom",
+                "last_name": "Nom",
+                "phone": "0645632569",
+                "email": "test@mail.fr",
+            },
+        )
+        assert response.status_code == 200
+        assert (
+            response.context["error_message"]
+            == "Trop de test item 1 commandés pour la quantité disponible"
+        )
+        assert not models.Order.objects.first()
+        assert not models.OrderAuthor.objects.first()
+
+    def test_order_no_item_available_anymore(self, client, other_user):
+        """a user an item that is not available anymore. They get an error"""
+        grouped_order = create_grouped_order(
+            days_before_delivery_date=5,
+            days_before_deadline=2,
+            name="gr order test",
+            orga_user=other_user,
+        )
+        item = models.Item.objects.create(
+            name="test item 1", grouped_order=grouped_order, price=1, max_limit=2
+        )
+        detail_url = reverse(
+            "order:grouped_order_detail",
+            kwargs={
+                "pk": grouped_order.pk,
+            },
+        )
+        response = client.get(detail_url)
+        assert response.status_code == 200
+        assert "test item" in response.content.decode()
+        assert "gr order test" in response.content.decode()
+        assert item.ordered_nb == 0
+        order_url = reverse(
+            "order:order",
+            kwargs={
+                "grouped_order_id": grouped_order.pk,
+            },
+        )
+        response = client.post(
+            order_url,
+            {
+                f"quantity_{item.pk}": 2,
+                "first_name": "Prénom",
+                "last_name": "Nom",
+                "phone": "0645632569",
+                "email": "test@mail.fr",
+            },
+        )
+        assert response.status_code == 302  # success : first order
+        response = client.post(
+            order_url,
+            {
+                f"quantity_{item.pk}": 1,
+                "first_name": "Prénom",
+                "last_name": "Nom",
+                "phone": "0645632569",
+                "email": "test@mail.fr",
+            },
+        )
+        assert response.status_code == 200  # error
+        assert (
+            response.context["error_message"]
+            == "Trop de test item 1 commandés pour la quantité disponible"
+        )
+
 
 class TestGroupedOrderOverview:
     def test_get_overview(self, client_log):
diff --git a/la_chariotte/order/views.py b/la_chariotte/order/views.py
index 68a0544..1fa091b 100644
--- a/la_chariotte/order/views.py
+++ b/la_chariotte/order/views.py
@@ -245,7 +245,7 @@ def validate_item_ordered_nb(item, ordered_nb):
     or if the ordered nb is negative"""
     if ordered_nb < 0:
         return f"Veuillez commander un nombre positif de {item.name}"
-    if item.get_remaining_nb() and item.get_remaining_nb() - ordered_nb < 0:
+    if item.get_remaining_nb() is not None and item.get_remaining_nb() - ordered_nb < 0:
         return f"Trop de {item.name} commandés pour la quantité disponible"
     return None