diff --git a/compensation/tests/compensation/test_workflow.py b/compensation/tests/compensation/test_workflow.py
index 570045f2..386c59c9 100644
--- a/compensation/tests/compensation/test_workflow.py
+++ b/compensation/tests/compensation/test_workflow.py
@@ -50,10 +50,11 @@ class CompensationWorkflowTestCase(BaseWorkflowTestCase):
         test_id = self.create_dummy_string()
         test_title = self.create_dummy_string()
         test_geom = self.create_dummy_geometry()
+        geom_json = self.create_geojson(test_geom)
         post_data = {
             "identifier": test_id,
             "title": test_title,
-            "geom": test_geom.geojson,
+            "geom": geom_json,
             "intervention": self.intervention.id,
         }
         pre_creation_intervention_log_count = self.intervention.log.count()
@@ -88,10 +89,11 @@ class CompensationWorkflowTestCase(BaseWorkflowTestCase):
         test_id = self.create_dummy_string()
         test_title = self.create_dummy_string()
         test_geom = self.create_dummy_geometry()
+        geom_json = self.create_geojson(test_geom)
         post_data = {
             "identifier": test_id,
             "title": test_title,
-            "geom": test_geom.geojson,
+            "geom": geom_json,
         }
         pre_creation_intervention_log_count = self.intervention.log.count()
 
diff --git a/compensation/tests/ecoaccount/test_workflow.py b/compensation/tests/ecoaccount/test_workflow.py
index bd6894ae..d1a3cf09 100644
--- a/compensation/tests/ecoaccount/test_workflow.py
+++ b/compensation/tests/ecoaccount/test_workflow.py
@@ -40,12 +40,13 @@ class EcoAccountWorkflowTestCase(BaseWorkflowTestCase):
         test_id = self.create_dummy_string()
         test_title = self.create_dummy_string()
         test_geom = self.create_dummy_geometry()
+        geom_json = self.create_geojson(test_geom)
         test_deductable_surface = 1000
         test_conservation_office = self.get_conservation_office_code()
         post_data = {
             "identifier": test_id,
             "title": test_title,
-            "geom": test_geom.geojson,
+            "geom": geom_json,
             "deductable_surface": test_deductable_surface,
             "conservation_office": test_conservation_office.id
         }
diff --git a/ema/tests/test_workflow.py b/ema/tests/test_workflow.py
index ecc3f195..4391fdc6 100644
--- a/ema/tests/test_workflow.py
+++ b/ema/tests/test_workflow.py
@@ -41,11 +41,12 @@ class EmaWorkflowTestCase(BaseWorkflowTestCase):
         test_id = self.create_dummy_string()
         test_title = self.create_dummy_string()
         test_geom = self.create_dummy_geometry()
+        geom_json = self.create_geojson(test_geom)
         test_conservation_office = self.get_conservation_office_code()
         post_data = {
             "identifier": test_id,
             "title": test_title,
-            "geom": test_geom.geojson,
+            "geom": geom_json,
             "conservation_office": test_conservation_office.id
         }
         self.client_user.post(new_url, post_data)
diff --git a/intervention/tests/test_workflow.py b/intervention/tests/test_workflow.py
index 66770977..9124c3e8 100644
--- a/intervention/tests/test_workflow.py
+++ b/intervention/tests/test_workflow.py
@@ -46,6 +46,7 @@ class InterventionWorkflowTestCase(BaseWorkflowTestCase):
         test_id = self.create_dummy_string()
         test_title = self.create_dummy_string()
         test_geom = self.create_dummy_geometry()
+        geom_json = self.create_geojson(test_geom)
 
         new_url = reverse("intervention:new", args=())
 
@@ -59,7 +60,7 @@ class InterventionWorkflowTestCase(BaseWorkflowTestCase):
         post_data = {
             "identifier": test_id,
             "title": test_title,
-            "geom": test_geom.geojson,
+            "geom": geom_json,
         }
         response = self.client_user.post(
             new_url,
diff --git a/konova/forms.py b/konova/forms.py
index 0d7f02fe..fec2966a 100644
--- a/konova/forms.py
+++ b/konova/forms.py
@@ -293,26 +293,33 @@ class SimpleGeomForm(BaseForm):
             geom = self.instance.geometry.geom
             geom.transform(ct=DEFAULT_SRID_RLP)
             self.empty = geom.empty
+            if self.empty:
+                raise AttributeError
             geom = geom.geojson
         except AttributeError:
             # If no geometry exists for this form, we simply set the value to None and zoom to the maximum level
             geom = ""
             self.empty = True
-            self.fields["geom"].widget.attrs["default_zoom"] = 1
 
         self.initialize_form_field("geom", geom)
 
     def is_valid(self):
-        super_valid = super().is_valid()
+        super().is_valid()
         is_valid = True
 
         # Get geojson from form
         geom = self.data["geom"]
         geom = json.loads(geom)
 
+        # Write submitted data back into form field to make sure invalid geometry
+        # will be rendered again on failed submit
+        self.initialize_form_field("geom", self.data["geom"])
+
         # Read geojson into gdal geometry
+        # HINT: This can be simplified if the geojson format holds data in epsg:4326 (GDAL provides direct creation for
+        # this case)
         features = []
-        features_json = geom["features"]
+        features_json = geom.get("features", [])
         for feature in features_json:
             g = gdal.OGRGeometry(json.dumps(feature["geometry"]), srs=DEFAULT_SRID_RLP)
             if g.geom_type not in ["Polygon", "MultiPolygon"]:
@@ -327,9 +334,12 @@ class SimpleGeomForm(BaseForm):
             form_geom.transform(coord_trans=DEFAULT_SRID)
             if form_geom.geom_type != "MultiPolygon":
                 form_geom = MultiPolygon(MultiPolygon.from_ewkt(form_geom.ewkt))
-            self.cleaned_data = {
-                "geom": form_geom.wkt
-            }
+
+            # Write unioned Multipolygon into cleaned data
+            if self.cleaned_data is None:
+                self.cleaned_data = {}
+            self.cleaned_data["geom"] = form_geom.wkt
+
         return is_valid
 
     def save(self, action: UserActionLogEntry):
diff --git a/konova/migrations/0010_auto_20220420_1034.py b/konova/migrations/0010_auto_20220420_1034.py
new file mode 100644
index 00000000..c916ff54
--- /dev/null
+++ b/konova/migrations/0010_auto_20220420_1034.py
@@ -0,0 +1,17 @@
+# Generated by Django 3.1.3 on 2022-04-20 08:34
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('konova', '0009_auto_20220411_1004'),
+    ]
+
+    operations = [
+        migrations.AddConstraint(
+            model_name='parcel',
+            constraint=models.UniqueConstraint(fields=('district', 'municipal', 'parcel_group', 'flr', 'flrstck_nnr', 'flrstck_zhlr'), name='Unique parcel constraint'),
+        ),
+    ]
diff --git a/konova/migrations/0011_auto_20220420_1101.py b/konova/migrations/0011_auto_20220420_1101.py
new file mode 100644
index 00000000..b402818e
--- /dev/null
+++ b/konova/migrations/0011_auto_20220420_1101.py
@@ -0,0 +1,25 @@
+# Generated by Django 3.1.3 on 2022-04-20 09:01
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('konova', '0010_auto_20220420_1034'),
+    ]
+
+    operations = [
+        migrations.AddConstraint(
+            model_name='district',
+            constraint=models.UniqueConstraint(fields=('key', 'name'), name='Unique district constraint'),
+        ),
+        migrations.AddConstraint(
+            model_name='municipal',
+            constraint=models.UniqueConstraint(fields=('key', 'name', 'district'), name='Unique municipal constraint'),
+        ),
+        migrations.AddConstraint(
+            model_name='parcelgroup',
+            constraint=models.UniqueConstraint(fields=('key', 'name', 'municipal'), name='Unique parcel group constraint'),
+        ),
+    ]
diff --git a/konova/models/geometry.py b/konova/models/geometry.py
index a71a2afa..3460c3dd 100644
--- a/konova/models/geometry.py
+++ b/konova/models/geometry.py
@@ -6,7 +6,7 @@ Created on: 15.11.21
 
 """
 from django.contrib.gis.db.models import MultiPolygonField
-from django.db import models
+from django.db import models, transaction
 from django.utils import timezone
 
 from konova.models import BaseResource, UuidModel
@@ -96,6 +96,7 @@ class Geometry(BaseResource):
             objs += set_objs
         return objs
 
+    @transaction.atomic
     def update_parcels(self):
         """ Updates underlying parcel information
 
diff --git a/konova/models/parcel.py b/konova/models/parcel.py
index f74b7af9..cc91e006 100644
--- a/konova/models/parcel.py
+++ b/konova/models/parcel.py
@@ -39,7 +39,17 @@ class District(UuidModel, AdministrativeSpatialReference):
     """ The model District refers to "Kreis"
 
     """
-    pass
+
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(
+                fields=[
+                    "key",
+                    "name",
+                ],
+                name="Unique district constraint"
+            )
+        ]
 
 
 class Municipal(UuidModel, AdministrativeSpatialReference):
@@ -53,6 +63,18 @@ class Municipal(UuidModel, AdministrativeSpatialReference):
         blank=True,
     )
 
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(
+                fields=[
+                    "key",
+                    "name",
+                    "district",
+                ],
+                name="Unique municipal constraint"
+            )
+        ]
+
 
 class ParcelGroup(UuidModel, AdministrativeSpatialReference):
     """ The model ParcelGroup refers to "Gemarkung", which is defined as a loose group of parcels
@@ -65,6 +87,18 @@ class ParcelGroup(UuidModel, AdministrativeSpatialReference):
         blank=True,
     )
 
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(
+                fields=[
+                    "key",
+                    "name",
+                    "municipal",
+                ],
+                name="Unique parcel group constraint"
+            )
+        ]
+
 
 class Parcel(UuidModel):
     """ The Parcel model holds administrative data on covered properties.
@@ -106,6 +140,21 @@ class Parcel(UuidModel):
     )
     updated_on = models.DateTimeField(auto_now_add=True)
 
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(
+                fields=[
+                    "district",
+                    "municipal",
+                    "parcel_group",
+                    "flr",
+                    "flrstck_nnr",
+                    "flrstck_zhlr",
+                ],
+                name="Unique parcel constraint"
+            )
+        ]
+
     def __str__(self):
         return f"{self.parcel_group} | {self.flr} | {self.flrstck_zhlr} | {self.flrstck_nnr}"
 
diff --git a/konova/tests/test_views.py b/konova/tests/test_views.py
index 28b3f8a2..dd3c0e14 100644
--- a/konova/tests/test_views.py
+++ b/konova/tests/test_views.py
@@ -6,9 +6,11 @@ Created on: 26.10.21
 
 """
 import datetime
+import json
 
 from codelist.settings import CODELIST_CONSERVATION_OFFICE_ID
 from ema.models import Ema
+from konova.sub_settings.lanis_settings import DEFAULT_SRID_RLP
 from user.models import User, Team
 from django.contrib.auth.models import Group
 from django.contrib.gis.geos import MultiPolygon, Polygon
@@ -287,8 +289,28 @@ class BaseTestCase(TestCase):
         """
         polygon = Polygon.from_bbox((7.592449, 50.359385, 7.593382, 50.359874))
         polygon.srid = 4326
-        polygon = polygon.transform(3857, clone=True)
-        return MultiPolygon(polygon, srid=3857)  # 3857 is the default srid used for MultiPolygonField in the form
+        polygon = polygon.transform(DEFAULT_SRID_RLP, clone=True)
+        return MultiPolygon(polygon, srid=DEFAULT_SRID_RLP)
+
+    def create_geojson(self, geometry):
+        """ Creates a default structure including geojson from a geometry
+
+        Args:
+            geometry ():
+
+        Returns:
+
+        """
+        geom_json = {
+            "features": [
+                {
+                    "type": "Feature",
+                    "geometry": json.loads(geometry.geojson),
+                }
+            ]
+        }
+        geom_json = json.dumps(geom_json)
+        return geom_json
 
     def create_dummy_handler(self) -> Handler:
         """ Creates a Handler
diff --git a/locale/de/LC_MESSAGES/django.mo b/locale/de/LC_MESSAGES/django.mo
index 9626e763..6eb446ee 100644
Binary files a/locale/de/LC_MESSAGES/django.mo and b/locale/de/LC_MESSAGES/django.mo differ
diff --git a/locale/de/LC_MESSAGES/django.po b/locale/de/LC_MESSAGES/django.po
index 2a78deb7..e5d9979d 100644
--- a/locale/de/LC_MESSAGES/django.po
+++ b/locale/de/LC_MESSAGES/django.po
@@ -18,15 +18,15 @@
 #: konova/filters/mixins.py:277 konova/filters/mixins.py:323
 #: konova/filters/mixins.py:361 konova/filters/mixins.py:362
 #: konova/filters/mixins.py:393 konova/filters/mixins.py:394
-#: konova/forms.py:177 konova/forms.py:278 konova/forms.py:349
-#: konova/forms.py:393 konova/forms.py:403 konova/forms.py:416
-#: konova/forms.py:428 konova/forms.py:446 user/forms.py:42
+#: konova/forms.py:179 konova/forms.py:281 konova/forms.py:382
+#: konova/forms.py:426 konova/forms.py:436 konova/forms.py:449
+#: konova/forms.py:461 konova/forms.py:479 user/forms.py:42
 #, fuzzy
 msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2022-04-19 13:28+0200\n"
+"POT-Creation-Date: 2022-04-20 09:51+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -77,7 +77,7 @@ msgstr "Bericht generieren"
 msgid "Select a timespan and the desired conservation office"
 msgstr "Wählen Sie die Zeitspanne und die gewünschte Eintragungsstelle"
 
-#: analysis/forms.py:69 konova/forms.py:225
+#: analysis/forms.py:69 konova/forms.py:227
 msgid "Continue"
 msgstr "Weiter"
 
@@ -342,7 +342,7 @@ msgstr "Automatisch generiert"
 #: intervention/templates/intervention/detail/includes/documents.html:28
 #: intervention/templates/intervention/detail/view.html:31
 #: intervention/templates/intervention/report/report.html:12
-#: konova/forms.py:392
+#: konova/forms.py:425
 msgid "Title"
 msgstr "Bezeichnung"
 
@@ -369,7 +369,7 @@ msgstr "Kompensation XY; Flur ABC"
 #: intervention/templates/intervention/detail/includes/documents.html:34
 #: intervention/templates/intervention/detail/includes/payments.html:34
 #: intervention/templates/intervention/detail/includes/revocation.html:38
-#: konova/forms.py:427 konova/templates/konova/includes/comment_card.html:16
+#: konova/forms.py:460 konova/templates/konova/includes/comment_card.html:16
 msgid "Comment"
 msgstr "Kommentar"
 
@@ -493,7 +493,7 @@ msgid "Due on which date"
 msgstr "Zahlung wird an diesem Datum erwartet"
 
 #: compensation/forms/modalForms.py:64 compensation/forms/modalForms.py:359
-#: intervention/forms/modalForms.py:177 konova/forms.py:429
+#: intervention/forms/modalForms.py:177 konova/forms.py:462
 msgid "Additional comment, maximum {} letters"
 msgstr "Zusätzlicher Kommentar, maximal {} Zeichen"
 
@@ -538,7 +538,7 @@ msgstr "Neuer Zustand"
 msgid "Insert data for the new state"
 msgstr "Geben Sie die Daten des neuen Zustandes ein"
 
-#: compensation/forms/modalForms.py:217 konova/forms.py:227
+#: compensation/forms/modalForms.py:217 konova/forms.py:229
 msgid "Object removed"
 msgstr "Objekt entfernt"
 
@@ -871,7 +871,7 @@ msgstr "Dokumente"
 #: compensation/templates/compensation/detail/eco_account/includes/documents.html:14
 #: ema/templates/ema/detail/includes/documents.html:14
 #: intervention/templates/intervention/detail/includes/documents.html:14
-#: konova/forms.py:445
+#: konova/forms.py:478
 msgid "Add new document"
 msgstr "Neues Dokument hinzufügen"
 
@@ -879,7 +879,7 @@ msgstr "Neues Dokument hinzufügen"
 #: compensation/templates/compensation/detail/eco_account/includes/documents.html:31
 #: ema/templates/ema/detail/includes/documents.html:31
 #: intervention/templates/intervention/detail/includes/documents.html:31
-#: konova/forms.py:402
+#: konova/forms.py:435
 msgid "Created on"
 msgstr "Erstellt"
 
@@ -887,7 +887,7 @@ msgstr "Erstellt"
 #: compensation/templates/compensation/detail/eco_account/includes/documents.html:61
 #: ema/templates/ema/detail/includes/documents.html:61
 #: intervention/templates/intervention/detail/includes/documents.html:65
-#: konova/forms.py:507
+#: konova/forms.py:540
 msgid "Edit document"
 msgstr "Dokument bearbeiten"
 
@@ -1316,7 +1316,7 @@ msgstr "Datum Bestandskraft"
 msgid "New intervention"
 msgstr "Neuer Eingriff"
 
-#: intervention/forms/forms.py:294
+#: intervention/forms/forms.py:298
 msgid "Edit intervention"
 msgstr "Eingriff bearbeiten"
 
@@ -1392,7 +1392,7 @@ msgstr "Kompensationen und Zahlungen geprüft"
 msgid "Run check"
 msgstr "Prüfung vornehmen"
 
-#: intervention/forms/modalForms.py:264 konova/forms.py:548
+#: intervention/forms/modalForms.py:264 konova/forms.py:581
 msgid ""
 "I, {} {}, confirm that all necessary control steps have been performed by "
 "myself."
@@ -1637,69 +1637,73 @@ msgstr "Nach Zulassungsbehörde suchen"
 msgid "Search for conservation office"
 msgstr "Nch Eintragungsstelle suchen"
 
-#: konova/forms.py:39 templates/form/collapsable/form.html:62
+#: konova/forms.py:41 templates/form/collapsable/form.html:62
 msgid "Save"
 msgstr "Speichern"
 
-#: konova/forms.py:73
+#: konova/forms.py:75
 msgid "Not editable"
 msgstr "Nicht editierbar"
 
-#: konova/forms.py:176 konova/forms.py:348
+#: konova/forms.py:178 konova/forms.py:381
 msgid "Confirm"
 msgstr "Bestätige"
 
-#: konova/forms.py:188 konova/forms.py:357
+#: konova/forms.py:190 konova/forms.py:390
 msgid "Remove"
 msgstr "Löschen"
 
-#: konova/forms.py:190
+#: konova/forms.py:192
 msgid "You are about to remove {} {}"
 msgstr "Sie sind dabei {} {} zu löschen"
 
-#: konova/forms.py:277 konova/utils/quality.py:44 konova/utils/quality.py:46
+#: konova/forms.py:280 konova/utils/quality.py:44 konova/utils/quality.py:46
 #: templates/form/collapsable/form.html:45
 msgid "Geometry"
 msgstr "Geometrie"
 
-#: konova/forms.py:358
+#: konova/forms.py:325
+msgid "Only surfaces allowed. Points or lines must be buffered."
+msgstr "Nur Flächen erlaubt. Punkte oder Linien müssen zu Flächen gepuffert werden."
+
+#: konova/forms.py:391
 msgid "Are you sure?"
 msgstr "Sind Sie sicher?"
 
-#: konova/forms.py:404
+#: konova/forms.py:437
 msgid "When has this file been created? Important for photos."
 msgstr "Wann wurde diese Datei erstellt oder das Foto aufgenommen?"
 
-#: konova/forms.py:415
+#: konova/forms.py:448
 #: venv/lib/python3.7/site-packages/django/db/models/fields/files.py:231
 msgid "File"
 msgstr "Datei"
 
-#: konova/forms.py:417
+#: konova/forms.py:450
 msgid "Allowed formats: pdf, jpg, png. Max size 15 MB."
 msgstr "Formate: pdf, jpg, png. Maximal 15 MB."
 
-#: konova/forms.py:482
+#: konova/forms.py:515
 msgid "Added document"
 msgstr "Dokument hinzugefügt"
 
-#: konova/forms.py:539
+#: konova/forms.py:572
 msgid "Confirm record"
 msgstr "Verzeichnen bestätigen"
 
-#: konova/forms.py:547
+#: konova/forms.py:580
 msgid "Record data"
 msgstr "Daten verzeichnen"
 
-#: konova/forms.py:554
+#: konova/forms.py:587
 msgid "Confirm unrecord"
 msgstr "Entzeichnen bestätigen"
 
-#: konova/forms.py:555
+#: konova/forms.py:588
 msgid "Unrecord data"
 msgstr "Daten entzeichnen"
 
-#: konova/forms.py:556
+#: konova/forms.py:589
 msgid "I, {} {}, confirm that this data must be unrecorded."
 msgstr ""
 "Ich, {} {}, bestätige, dass diese Daten wieder entzeichnet werden müssen."
@@ -2066,7 +2070,7 @@ msgstr "{} wurde erfolgreich vom Nutzer {} geprüft! {}"
 msgid "missing"
 msgstr "fehlt"
 
-#: konova/views.py:96 templates/navbars/navbar.html:16
+#: konova/views.py:99 templates/navbars/navbar.html:16
 msgid "Home"
 msgstr "Home"