diff --git a/settings/common.py b/settings/common.py
index c1a60956..2b41d7d8 100644
--- a/settings/common.py
+++ b/settings/common.py
@@ -549,6 +549,8 @@ MAX_PUBLIC_PROJECTS_PER_USER = None # None == no limit
 MAX_MEMBERSHIPS_PRIVATE_PROJECTS = None # None == no limit
 MAX_MEMBERSHIPS_PUBLIC_PROJECTS = None # None == no limit
 
+MAX_PENDING_MEMBERSHIPS = 30 # Max number of unconfirmed memberships in a project
+
 from .sr import *
 
 
diff --git a/taiga/projects/services/members.py b/taiga/projects/services/members.py
index 3cd9b514..52c62eca 100644
--- a/taiga/projects/services/members.py
+++ b/taiga/projects/services/members.py
@@ -20,6 +20,7 @@ from taiga.base.exceptions import ValidationError
 from taiga.base.utils import db, text
 from taiga.users.models import User
 
+from django.conf import settings
 from django.core.validators import validate_email
 from django.utils.translation import ugettext as _
 
@@ -143,4 +144,8 @@ def check_if_project_can_have_more_memberships(project, total_new_memberships):
     if max_memberships is not None and total_memberships > max_memberships:
         return False, error_members_exceeded
 
+    if project.memberships.filter(user=None).count() + total_new_memberships > settings.MAX_PENDING_MEMBERSHIPS:
+        error_pending_memberships_exceeded = _("You have reached the current limit of pending memberships")
+        return False, error_pending_memberships_exceeded
+
     return True, None
diff --git a/tests/integration/test_memberships.py b/tests/integration/test_memberships.py
index b9c3dc95..16d642bf 100644
--- a/tests/integration/test_memberships.py
+++ b/tests/integration/test_memberships.py
@@ -657,3 +657,43 @@ def test_api_delete_membership_without_user(client):
     response = client.json.delete(url)
 
     assert response.status_code == 204
+
+
+def test_api_create_member_max_pending_memberships(client, settings):
+    settings.MAX_PENDING_MEMBERSHIPS = 2
+    project = f.ProjectFactory()
+    john = f.UserFactory.create()
+    joseph = f.UserFactory.create()
+    tester = f.RoleFactory(project=project, name="Tester")
+    f.MembershipFactory(project=project, user=john, is_admin=True)
+    f.MembershipFactory(project=project, user=None)
+    f.MembershipFactory(project=project, user=None)
+
+    url = reverse("memberships-list")
+    data = {"project": project.id, "role": tester.id, "username": joseph.email}
+    client.login(john)
+    response = client.json.post(url, json.dumps(data))
+    assert response.status_code == 400
+    assert "limit of pending memberships" in response.data["_error_message"]
+
+
+def test_api_create_bulk_members_max_pending_memberships(client, settings):
+    settings.MAX_PENDING_MEMBERSHIPS = 2
+    project = f.ProjectFactory()
+    john = f.UserFactory.create()
+    joseph = f.UserFactory.create()
+    tester = f.RoleFactory(project=project, name="Tester")
+    f.MembershipFactory(project=project, user=john, is_admin=True)
+    f.MembershipFactory(project=project, user=None)
+    f.MembershipFactory(project=project, user=None)
+
+    url = reverse("memberships-bulk-create")
+    data = {
+        "project_id": project.id,
+        "bulk_memberships": [
+            {"role_id": tester.id, "username": "testing@taiga.io"},
+        ]
+    }
+    client.login(john)
+    response = client.json.post(url, json.dumps(data))
+    assert response.status_code == 400