diff --git a/dref/migrations/0066_auto_20230803_0758.py b/dref/migrations/0066_auto_20230803_0758.py
new file mode 100644
index 000000000..7db5f1833
--- /dev/null
+++ b/dref/migrations/0066_auto_20230803_0758.py
@@ -0,0 +1,46 @@
+# Generated by Django 3.2.20 on 2023-08-03 07:58
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('dref', '0065_auto_20230728_0405'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='dref',
+            name='created_by',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='created_by_dref', to=settings.AUTH_USER_MODEL, verbose_name='created by'),
+        ),
+        migrations.AlterField(
+            model_name='dref',
+            name='modified_by',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='modified_by_dref', to=settings.AUTH_USER_MODEL, verbose_name='modified by'),
+        ),
+        migrations.AlterField(
+            model_name='dreffinalreport',
+            name='created_by',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='created_by_dref_final_report', to=settings.AUTH_USER_MODEL, verbose_name='created by'),
+        ),
+        migrations.AlterField(
+            model_name='dreffinalreport',
+            name='modified_by',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='modified_by_dref_final_report', to=settings.AUTH_USER_MODEL, verbose_name='modified by'),
+        ),
+        migrations.AlterField(
+            model_name='drefoperationalupdate',
+            name='created_by',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='created_by_dref_operational_update', to=settings.AUTH_USER_MODEL, verbose_name='created by'),
+        ),
+        migrations.AlterField(
+            model_name='drefoperationalupdate',
+            name='modified_by',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='modified_by_dref_operational_update', to=settings.AUTH_USER_MODEL, verbose_name='modified by'),
+        ),
+    ]
diff --git a/dref/models.py b/dref/models.py
index 19dd2c884..0fc9ed053 100644
--- a/dref/models.py
+++ b/dref/models.py
@@ -230,14 +230,14 @@ class Status(models.IntegerChoices):
         settings.AUTH_USER_MODEL,
         verbose_name=_("created by"),
         on_delete=models.SET_NULL,
-        null=True,
+        null=True, blank=True,
         related_name="created_by_dref",
     )
     modified_by = models.ForeignKey(
         settings.AUTH_USER_MODEL,
         verbose_name=_("modified by"),
         on_delete=models.SET_NULL,
-        null=True,
+        null=True, blank=True,
         related_name="modified_by_dref",
     )
     users = models.ManyToManyField(settings.AUTH_USER_MODEL, verbose_name=_("users"), blank=True, related_name="user_dref")
@@ -582,6 +582,7 @@ class Meta:
         verbose_name_plural = _("drefs")
 
     def save(self, *args, **kwargs):
+        self.full_clean()  # required for choice field validation
         if self.budget_file and self.budget_file_id != self.__budget_file_id:
             pages = convert_from_bytes(self.budget_file.file.read())
             if len(pages) > 0:
@@ -666,14 +667,14 @@ class DrefOperationalUpdate(models.Model):
         settings.AUTH_USER_MODEL,
         verbose_name=_("created by"),
         on_delete=models.SET_NULL,
-        null=True,
+        null=True, blank=True,
         related_name="created_by_dref_operational_update",
     )
     modified_by = models.ForeignKey(
         settings.AUTH_USER_MODEL,
         verbose_name=_("modified by"),
         on_delete=models.SET_NULL,
-        null=True,
+        null=True, blank=True,
         related_name="modified_by_dref_operational_update",
     )
     dref = models.ForeignKey(Dref, verbose_name=_("Dref"), on_delete=models.CASCADE)
@@ -994,6 +995,7 @@ class Meta:
 
     def save(self, *args, **kwargs):
         # self.status = Dref.Status.COMPLETED if self.is_published else Dref.Status.IN_PROGRESS
+        self.full_clean()  # required for choice field validation
         super().save(*args, **kwargs)
 
     @staticmethod
@@ -1024,14 +1026,14 @@ class DrefFinalReport(models.Model):
         settings.AUTH_USER_MODEL,
         verbose_name=_("created by"),
         on_delete=models.SET_NULL,
-        null=True,
+        null=True, blank=True,
         related_name="created_by_dref_final_report",
     )
     modified_by = models.ForeignKey(
         settings.AUTH_USER_MODEL,
         verbose_name=_("modified by"),
         on_delete=models.SET_NULL,
-        null=True,
+        null=True, blank=True,
         related_name="modified_by_dref_final_report",
     )
     dref = models.OneToOneField(Dref, verbose_name=_("Dref"), on_delete=models.CASCADE)
@@ -1291,6 +1293,7 @@ class Meta:
         verbose_name_plural = _("Dref Final Reports")
 
     def save(self, *args, **kwargs):
+        self.full_clean()  # required for choice field validation
         if self.financial_report_id and self.financial_report_id != self.__financial_report_id:
             pages = convert_from_bytes(self.financial_report.file.read())
             if len(pages) > 0: