diff --git a/rero_ils/modules/local_fields/api.py b/rero_ils/modules/local_fields/api.py
index 4844416b12..4ca6d474af 100644
--- a/rero_ils/modules/local_fields/api.py
+++ b/rero_ils/modules/local_fields/api.py
@@ -66,6 +66,22 @@ class LocalField(IlsRecord):
 
     def extended_validation(self, **kwargs):
         """Extended validation."""
+        from .api import LocalFieldsSearch
+
+        # check if a local_fields resource exists for this document
+        type = extracted_data_from_ref(self.get('parent'), data='resource')
+        document_pid = extracted_data_from_ref(self.get('parent'))
+        organisation_pid = extracted_data_from_ref(self.get('organisation'))
+        count = LocalFieldsSearch()\
+            .filter('term', parent__type=type)\
+            .filter('term', parent__pid=document_pid)\
+            .filter('term', organisation__pid=organisation_pid)\
+            .filter('bool', must_not=[Q('term', pid=self['pid'])])\
+            .count()
+        if count > 0:
+            return _('Local fields already exist for this document.')
+
+        # check if all fields are empty.
         if len(self.get('fields', {}).keys()) == 0:
             return _('Missing fields.')
         return True
diff --git a/tests/api/local_fields/test_local_fields_rest.py b/tests/api/local_fields/test_local_fields_rest.py
new file mode 100644
index 0000000000..ca35d9d129
--- /dev/null
+++ b/tests/api/local_fields/test_local_fields_rest.py
@@ -0,0 +1,122 @@
+# -*- coding: utf-8 -*-
+#
+# RERO ILS
+# Copyright (C) 2020 RERO
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, version 3 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+"""Tests REST API local fields."""
+
+import json
+from copy import deepcopy
+
+import mock
+from flask import url_for
+from utils import VerifyRecordPermissionPatch, get_json, postdata
+
+
+def test_local_fields_permissions(client, org_martigny, document,
+                                  local_field_martigny, json_header):
+    """Test permissions on local fields."""
+    local_fields_url = url_for(
+        'invenio_records_rest.lofi_item', pid_value='lofi1')
+    res = client.get(local_fields_url)
+    assert res.status_code == 401
+
+    res, _ = postdata(client, 'invenio_records_rest.lofi_list', {})
+    assert res.status_code == 401
+
+    res = client.put(
+        url_for('invenio_records_rest.lofi_item', pid_value='lofi1'),
+        data={},
+        headers=json_header
+    )
+    assert res.status_code == 401
+
+    res = client.delete(local_fields_url)
+    assert res.status_code == 401
+
+
+@mock.patch('invenio_records_rest.views.verify_record_permission',
+            mock.MagicMock(return_value=VerifyRecordPermissionPatch))
+def test_local_fields_get(client, org_martigny, document,
+                          local_field_martigny):
+    """Test GET on local fields."""
+    local_fields_url = url_for(
+        'invenio_records_rest.lofi_item', pid_value='lofi1')
+    res = client.get(local_fields_url)
+    assert res.status_code == 200
+
+    data = get_json(res)
+    assert local_field_martigny == data['metadata']
+
+    list_url = url_for('invenio_records_rest.lofi_list', pid='lofi1')
+    res = client.get(list_url)
+    assert res.status_code == 200
+    data = get_json(res)
+    assert data['hits']['hits'][0]['metadata'] == \
+        local_field_martigny.replace_refs()
+
+
+@mock.patch('invenio_records_rest.views.verify_record_permission',
+            mock.MagicMock(return_value=VerifyRecordPermissionPatch))
+def test_local_fields_post_put_delete(client, org_sion, document,
+                                      local_field_sion_data, json_header):
+    """Test POST and PUT on local fields."""
+    lf_pid = local_field_sion_data['pid']
+    item_url = url_for('invenio_records_rest.lofi_item', pid_value=lf_pid)
+    list_url = url_for('invenio_records_rest.lofi_list', q=f'pid:{lf_pid}')
+
+    res, data = postdata(client, 'invenio_records_rest.lofi_list',
+                         local_field_sion_data)
+    assert res.status_code == 201
+
+    assert data['metadata'] == local_field_sion_data
+
+    res = client.get(item_url)
+    assert res.status_code == 200
+    data = get_json(res)
+    assert local_field_sion_data == data['metadata']
+
+    data = deepcopy(local_field_sion_data)
+    data['fields']['field_2'] = ['field 2']
+    res = client.put(
+        item_url,
+        data=json.dumps(data),
+        headers=json_header
+    )
+    assert res.status_code == 200
+
+    data = get_json(res)
+    assert data['metadata']['fields']['field_2'][0] == 'field 2'
+
+    res = client.get(list_url)
+    assert res.status_code == 200
+    data = get_json(res)['hits']['hits'][0]
+    assert data['metadata']['fields']['field_2'][0] == 'field 2'
+
+    # Check duplicate record
+    res, _ = postdata(client, 'invenio_records_rest.lofi_list', data)
+    assert res.status_code == 400
+
+    res = client.get(url_for(
+        'invenio_records_rest.lofi_list',
+        q=f'organisation.pid:{data["metadata"]["organisation"]["pid"]}'))
+    data = get_json(res)
+    assert data['hits']['total']['value'] == 1
+
+    # Delete record
+    res = client.delete(item_url)
+    assert res.status_code == 204
+
+    res = client.get(item_url)
+    assert res.status_code == 410