diff --git a/README.md b/README.md
index 79fb0db..b8ea722 100644
--- a/README.md
+++ b/README.md
@@ -88,4 +88,5 @@ Add support for Netbox 3.5 which become the minimum version supported to accomod
 
 * Add bulk update capability for contract assignement
 * [#63](https://github.com/mlebreuil/netbox-contract/issues/63) Correct an API issue on the invoice object.
+* [#64](https://github.com/mlebreuil/netbox-contract/issues/64) Add hierarchy to contract; New parent field created.
 
diff --git a/src/netbox_contract/api/serializers.py b/src/netbox_contract/api/serializers.py
index dca290a..1a9b47c 100644
--- a/src/netbox_contract/api/serializers.py
+++ b/src/netbox_contract/api/serializers.py
@@ -50,11 +50,12 @@ class ContractSerializer(NetBoxModelSerializer):
     )
     circuit= NestedCircuitSerializer(many=True, required=False)
     external_partie = NestedServiceProviderSerializer(many=False)
+    parent = NestedContracSerializer(many=False, required=False)
 
     class Meta:
         model = Contract
         fields = (
-            'id', 'url','display', 'name', 'status', 'external_partie','internal_partie','circuit','comments',
+            'id', 'url','display', 'name', 'status', 'external_partie','internal_partie','parent','circuit','comments',
             'tags', 'custom_fields', 'created', 'last_updated',
         )
 
diff --git a/src/netbox_contract/api/views.py b/src/netbox_contract/api/views.py
index 24de632..9a5fd15 100644
--- a/src/netbox_contract/api/views.py
+++ b/src/netbox_contract/api/views.py
@@ -4,7 +4,9 @@
 from .serializers import ContractSerializer, InvoiceSerializer, ServiceProviderSerializer, ContractAssignementSerializer
 
 class ContractViewSet(NetBoxModelViewSet):
-    queryset = models.Contract.objects.prefetch_related('circuit','tags')
+    queryset = models.Contract.objects.prefetch_related(
+        'parent','circuit','tags'
+        )
     serializer_class = ContractSerializer
 
 class InvoiceViewSet(NetBoxModelViewSet):
diff --git a/src/netbox_contract/filtersets.py b/src/netbox_contract/filtersets.py
index 2cfe177..dbfb748 100644
--- a/src/netbox_contract/filtersets.py
+++ b/src/netbox_contract/filtersets.py
@@ -7,7 +7,7 @@ class ContractFilterSet(NetBoxModelFilterSet):
 
     class Meta:
         model = Contract
-        fields = ('id', 'external_partie', 'internal_partie', 'status','circuit')
+        fields = ('id', 'external_partie', 'internal_partie', 'status','parent','circuit')
 
     def search(self, queryset, name, value):
         return queryset.filter( Q(name__icontains=value)
diff --git a/src/netbox_contract/forms.py b/src/netbox_contract/forms.py
index f3adc47..3d90a0b 100644
--- a/src/netbox_contract/forms.py
+++ b/src/netbox_contract/forms.py
@@ -17,12 +17,16 @@ class ContractForm(NetBoxModelForm):
     external_partie=DynamicModelChoiceField(
         queryset=ServiceProvider.objects.all()
     )
+    parent=DynamicModelChoiceField(
+        queryset=Contract.objects.all(),
+        required=False
+    )
 
     class Meta:
         model = Contract
         fields = ('name', 'external_partie', 'external_reference', 'internal_partie','tenant', 'status',
           'start_date', 'end_date','initial_term', 'renewal_term', 'currency','accounting_dimensions',
-          'mrc', 'nrc','invoice_frequency','circuit', 'documents', 'comments', 'tags')
+          'mrc', 'nrc','invoice_frequency','circuit','parent','documents', 'comments', 'tags')
 
         widgets = {
             'start_date': DatePicker(),
@@ -47,7 +51,7 @@ class Meta:
 
 class ContractFilterSetForm(NetBoxModelFilterSetForm):
     model = Contract
-    external_partie=DynamicModelMultipleChoiceField(
+    external_partie=DynamicModelChoiceField(
         queryset=ServiceProvider.objects.all(),
         required=False
     )
@@ -65,6 +69,10 @@ class ContractFilterSetForm(NetBoxModelFilterSetForm):
         queryset=Circuit.objects.all(),
         required=False
     )
+    parent=DynamicModelChoiceField(
+        queryset=Contract.objects.all(),
+        required=False
+    )
 
 class InvoiceFilterSetForm(NetBoxModelFilterSetForm):
     model = Invoice
@@ -77,7 +85,8 @@ class ContractCSVForm(NetBoxModelImportForm):
     circuit = CSVModelChoiceField(
         queryset=Circuit.objects.all(),
         to_field_name='name',
-        help_text='Related Circuit'
+        help_text='Related Circuit',
+        required=False
     )
 
     class Meta:
@@ -85,7 +94,7 @@ class Meta:
         fields = [
             'name', 'external_partie', 'internal_partie','tenant', 'status',
             'start_date', 'initial_term', 'renewal_term', 'mrc', 'nrc',
-            'invoice_frequency', 'circuit'
+            'invoice_frequency', 'parent','circuit'
         ]
 
 class ContractBulkEditForm(NetBoxModelBulkEditForm):
@@ -93,9 +102,9 @@ class ContractBulkEditForm(NetBoxModelBulkEditForm):
         max_length=100,
         required=True
     )
-    external_partie = forms.CharField(
-        max_length=30,
-        required=True
+    external_partie = DynamicModelChoiceField(
+        queryset=ServiceProvider.objects.all(),
+        required=False
     )
     external_reference=forms.CharField(
         max_length=100,
@@ -107,7 +116,12 @@ class ContractBulkEditForm(NetBoxModelBulkEditForm):
     )
     comments = CommentField()
     circuit=DynamicModelChoiceField(
-        queryset=Circuit.objects.all()
+        queryset=Circuit.objects.all(),
+        required=False
+    )
+    parent = DynamicModelChoiceField(
+        queryset=Contract.objects.all(),
+        required=False
     )
 
     nullable_fields = (
diff --git a/src/netbox_contract/migrations/0016_contract_parent.py b/src/netbox_contract/migrations/0016_contract_parent.py
new file mode 100644
index 0000000..eead24f
--- /dev/null
+++ b/src/netbox_contract/migrations/0016_contract_parent.py
@@ -0,0 +1,25 @@
+# Generated by Django 4.1.9 on 2023-06-18 14:45
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("netbox_contract", "0015_contractassignement"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="contract",
+            name="parent",
+            field=models.ForeignKey(
+                blank=True,
+                null=True,
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="child",
+                to="netbox_contract.contract",
+            ),
+        ),
+    ]
diff --git a/src/netbox_contract/models.py b/src/netbox_contract/models.py
index 6254d51..f10a189 100644
--- a/src/netbox_contract/models.py
+++ b/src/netbox_contract/models.py
@@ -172,6 +172,13 @@ class Contract(NetBoxModel):
     comments = models.TextField(
         blank=True
     )
+    parent = models.ForeignKey(
+        'self',
+        on_delete=models.CASCADE,
+        related_name='child',
+        null=True,
+        blank=True
+    )
 
     def get_absolute_url(self):
         return reverse('plugins:netbox_contract:contract', args=[self.pk])
diff --git a/src/netbox_contract/tables.py b/src/netbox_contract/tables.py
index ab9b899..397f1c9 100644
--- a/src/netbox_contract/tables.py
+++ b/src/netbox_contract/tables.py
@@ -63,13 +63,16 @@ class ContractListTable(NetBoxTable):
         linkify=True
     )
     circuit = tables.ManyToManyColumn()
+    parent = tables.Column(
+        linkify=True
+    )
 
     class Meta(NetBoxTable.Meta):
         model = Contract
         fields = ('pk', 'id', 'name', 'circuit', 'external_partie',
          'external_reference','internal_partie', 'status', 'mrc',
-         'comments', 'actions')
-        default_columns = ('name', 'status', 'circuit')
+         'parent','comments', 'actions')
+        default_columns = ('name', 'status', 'parent','circuit')
 
 class ContractListBottomTable(NetBoxTable):
     name = tables.Column(
diff --git a/src/netbox_contract/templates/netbox_contract/contract.html b/src/netbox_contract/templates/netbox_contract/contract.html
index 708b560..19981bd 100644
--- a/src/netbox_contract/templates/netbox_contract/contract.html
+++ b/src/netbox_contract/templates/netbox_contract/contract.html
@@ -73,6 +73,12 @@ <h5 class="card-header">Contract</h5>
               <th scope="row">Invoice frequency</th>
               <td>{{ object.invoice_frequency }}</td>
             </tr>
+            <tr>
+              <th scope="row">Parent</th>
+              <td>
+                <a href="{{ object.parent.get_absolute_url }}">{{ object.parent.name }}</a>
+              </td>
+            </tr>
             {% if object.documents %}
             <tr>
               <th scope="row">Documents</th>