diff --git a/fet2020/finance/forms.py b/fet2020/finance/forms.py
index 3232c990..704d4295 100644
--- a/fet2020/finance/forms.py
+++ b/fet2020/finance/forms.py
@@ -108,9 +108,9 @@ class BillCreateForm(forms.ModelForm):
         super().__init__(*args, **kwargs)  # to get the self.fields set
 
         member = Member.objects.get(username=user.username)
-
         self.fields["bill_creator"].initial = member
         self.fields["bill_creator"].disabled = True
+        self.fields["bill_creator"].required = True
 
         self.fields["invoice"].placeholder = "Firmenname\nStraße\nPLZ und Ort"
         self.fields["invoice"].cols = 30
@@ -191,6 +191,7 @@ class BillUpdateForm(forms.ModelForm):
 
         self.fields["bill_creator"].initial = kwargs["instance"].bill_creator
         self.fields["bill_creator"].disabled = True
+        self.fields["bill_creator"].required = True
 
         self.fields["status"].disabled = True
 
diff --git a/fet2020/finance/migrations/0003_alter_bill_bill_creator.py b/fet2020/finance/migrations/0003_alter_bill_bill_creator.py
new file mode 100644
index 00000000..ba576a5b
--- /dev/null
+++ b/fet2020/finance/migrations/0003_alter_bill_bill_creator.py
@@ -0,0 +1,26 @@
+# Generated by Django 4.2.10 on 2024-02-17 10:45
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("members", "0005_alter_job_options_job_order_alter_member_username"),
+        ("finance", "0002_wiref_status_alter_bill_affiliation_alter_bill_payer"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="bill",
+            name="bill_creator",
+            field=models.ForeignKey(
+                blank=True,
+                null=True,
+                on_delete=django.db.models.deletion.PROTECT,
+                to="members.member",
+                verbose_name="Verantwortliche:r",
+            ),
+        ),
+    ]
diff --git a/fet2020/finance/models.py b/fet2020/finance/models.py
index 4dd796ee..40b3e787 100644
--- a/fet2020/finance/models.py
+++ b/fet2020/finance/models.py
@@ -117,7 +117,7 @@ class Wiref(models.Model):
 class Bill(models.Model):
     # members can be deleted but never their bills
     bill_creator = models.ForeignKey(
-        Member, on_delete=models.PROTECT, verbose_name="Verantwortliche:r"
+        Member, on_delete=models.PROTECT, blank=True, null=True, verbose_name="Verantwortliche:r"
     )
 
     bankdata = models.ForeignKey(