diff --git a/musician/models.py b/musician/models.py
index bccd595..3239829 100644
--- a/musician/models.py
+++ b/musician/models.py
@@ -34,6 +34,8 @@ class OrchestraModel:
         Args:
             data: A JSON dict, as converted from the JSON in the orchestra API.
         """
+        if data is None:
+            return cls()
 
         json_data = data.copy()
         if kwargs:
diff --git a/musician/settings.py b/musician/settings.py
index 1fafdd2..6ef7f86 100644
--- a/musician/settings.py
+++ b/musician/settings.py
@@ -1,3 +1,4 @@
+from collections import defaultdict
 from django.conf import settings
 
 
@@ -5,22 +6,28 @@ def getsetting(name):
     value = getattr(settings, name, None)
     return value or DEFAULTS.get(name)
 
+# provide a default value allowing to overwrite it for each type of account
+def allowed_resources_default_factory():
+    return {'mailbox': 2}
 
 DEFAULTS = {
     # allowed resources limit hardcoded because cannot be retrieved from the API.
-    "ALLOWED_RESOURCES": {
-        'INDIVIDUAL':
+    "ALLOWED_RESOURCES": defaultdict(
+        allowed_resources_default_factory,
         {
-            # 'disk': 1024,
-            # 'traffic': 2048,
-            'mailbox': 2,
-        },
-        'ASSOCIATION': {
-            # 'disk': 5 * 1024,
-            # 'traffic': 20 * 1024,
-            'mailbox': 10,
+            'INDIVIDUAL':
+            {
+                # 'disk': 1024,
+                # 'traffic': 2048,
+                'mailbox': 2,
+            },
+            'ASSOCIATION': {
+                # 'disk': 5 * 1024,
+                # 'traffic': 20 * 1024,
+                'mailbox': 10,
+            }
         }
-    },
+    ),
     "URL_DB_PHPMYADMIN": "https://phpmyadmin.pangea.org/",
     "URL_MAILTRAIN": "https://mailtrain.org/",
     "URL_SAAS_GITLAB": "https://gitlab.pangea.org/",
diff --git a/musician/tests.py b/musician/tests.py
index 44118a2..8becf4d 100644
--- a/musician/tests.py
+++ b/musician/tests.py
@@ -62,6 +62,31 @@ class UserAccountTest(TestCase):
         account = UserAccount.new_from_json(data)
         self.assertIsNone(account.last_login)
 
+    def test_user_without_billcontact(self):
+        data = {
+            'billcontact': None,
+            'date_joined': '2020-03-05T09:49:21Z',
+            'full_name': 'David Rock',
+            'id': 2,
+            'is_active': True,
+            'language': 'CA',
+            'last_login': '2020-03-19T10:21:49.504266Z',
+            'resources': [{'allocated': None,
+                           'name': 'disk',
+                           'unit': 'GiB',
+                           'used': '0.000'},
+                          {'allocated': None,
+                           'name': 'traffic',
+                           'unit': 'GiB',
+                           'used': '0.000'}],
+            'short_name': '',
+            'type': 'STAFF',
+            'url': 'https://example.org/api/accounts/2/',
+            'username': 'drock'
+        }
+        account = UserAccount.new_from_json(data)
+        self.assertIsNotNone(account.billing)
+
 
 class GetBootstrapedPercentTest(TestCase):
     BS_WIDTH = [0, 25, 50, 100]