diff --git a/pontoon/base/models/user.py b/pontoon/base/models/user.py
index d2f7b63b04..8bfd8b0034 100644
--- a/pontoon/base/models/user.py
+++ b/pontoon/base/models/user.py
@@ -281,12 +281,13 @@ def can_translate(self, locale, project):
     return self.has_perm("base.can_translate_locale", locale)
 
 
-def is_new_contributor(self, locale):
-    """Return True if the user hasn't made contributions to the locale yet."""
+def has_one_contribution(self, locale):
+    """Return True if the user has made just 1 contribution to the locale."""
     return (
-        not self.translation_set.filter(locale=locale)
+        self.translation_set.filter(locale=locale)
         .exclude(entity__resource__project__system_project=True)
-        .exists()
+        .count()
+        == 1
     )
 
 
@@ -499,7 +500,7 @@ def latest_action(self):
 User.add_to_class("has_approved_translations", has_approved_translations)
 User.add_to_class("top_contributed_locale", top_contributed_locale)
 User.add_to_class("can_translate", can_translate)
-User.add_to_class("is_new_contributor", is_new_contributor)
+User.add_to_class("has_one_contribution", has_one_contribution)
 User.add_to_class("notification_list", notification_list)
 User.add_to_class("menu_notifications", menu_notifications)
 User.add_to_class("unread_notifications_display", unread_notifications_display)
diff --git a/pontoon/translations/tests/test_views.py b/pontoon/translations/tests/test_views.py
index 42b4d26271..f3493c86c2 100644
--- a/pontoon/translations/tests/test_views.py
+++ b/pontoon/translations/tests/test_views.py
@@ -1,3 +1,5 @@
+from unittest.mock import patch
+
 import pytest
 
 from django.urls import reverse
@@ -210,6 +212,76 @@ def test_run_checks_during_translation_update(
     assert warning.message == "trailing argument 1 `s` missing"
 
 
+@patch("notifications.signals.notify.send")
+@pytest.mark.django_db
+def test_notify_managers_on_first_contribution(
+    mock_notify,
+    member,
+    entity_a,
+    entity_b,
+    locale_a,
+    user_a,
+    user_b,
+    project_locale_a,
+    request_create_translation,
+):
+    """
+    Test that managers are notified when a user makes their first contribution
+    to a locale.
+    """
+    translation = TranslationFactory(
+        entity=entity_a,
+        locale=locale_a,
+        user=user_b,  # user_b has no contributions to locale_a yet
+        approved=True,
+        active=True,
+    )
+
+    # Set user_a as a manager for locale_a and subscribe it to new contributor notifications
+    translation.locale.managers_group.user_set.add(user_a)
+    user_a.profile.new_contributor_notifications = True
+    user_a.profile.save()
+
+    mock_notify.reset_mock()
+    response = request_create_translation(
+        member.client,
+        entity=translation.entity.pk,
+        original=translation.entity.string,
+        locale=translation.locale.code,
+        translation="First translation",
+    )
+
+    assert response.status_code == 200
+    assert response.json()["status"]
+
+    mock_notify.assert_called_once()
+
+    # Check that the new contributor notification was sent to the correct manager
+    notify_args = mock_notify.call_args[1]
+    assert notify_args["recipient"] == user_a
+    assert notify_args["category"] == "new_contributor"
+
+    # Check that the new contributor notification is only sent for the first contribution
+    second_translation = TranslationFactory(
+        entity=entity_b,
+        locale=locale_a,
+        user=user_b,
+        approved=True,
+        active=True,
+    )
+
+    mock_notify.reset_mock()
+    response = request_create_translation(
+        member.client,
+        entity=second_translation.entity.pk,
+        original=second_translation.entity.string,
+        locale=second_translation.locale.code,
+        translation="Second translation",
+    )
+
+    mock_notify.assert_not_called()
+
+
 @pytest.fixture
 def approved_translation(locale_a, project_locale_a, entity_a, user_a):
     return TranslationFactory(
diff --git a/pontoon/translations/views.py b/pontoon/translations/views.py
index 726441cc03..122041d7e4 100644
--- a/pontoon/translations/views.py
+++ b/pontoon/translations/views.py
@@ -126,7 +126,11 @@ def create_translation(request):
         )
 
     # When user makes their first contribution to the team, notify team managers
-    first_contribution = not project.system_project and user.is_new_contributor(locale)
+    first_contribution = (
+        not project.system_project
+        and user != project.contact
+        and user.has_one_contribution(locale)
+    )
     if first_contribution:
         description = render_to_string(
             "messaging/notifications/new_contributor.html",