diff --git a/app/user/rest.py b/app/user/rest.py
index f6322aae3..51595f603 100644
--- a/app/user/rest.py
+++ b/app/user/rest.py
@@ -63,6 +63,7 @@ from app.user.users_schema import (
     post_send_user_sms_code_schema,
     post_set_permissions_schema,
     post_verify_code_schema,
+    post_verify_webauthn_schema,
 )
 from app.utils import url_with_token
 
@@ -226,6 +227,32 @@ def verify_user_code(user_id):
     return jsonify({}), 204
 
 
+@user_blueprint.route('/<uuid:user_id>/verify/webauthn-login', methods=['POST'])
+def verify_webauthn_login_for_user(user_id):
+    """
+    webauthn logins are already verified on the admin app but we still need to
+    check the max login count and set up a session id etc here.
+    """
+    data = request.get_json()
+    validate(data, post_verify_webauthn_schema)
+
+    user = get_user_by_id(user_id=user_id)
+    successful = data['successful']
+
+    if user.failed_login_count >= current_app.config.get('MAX_VERIFY_CODE_COUNT'):
+        raise InvalidRequest("Maximum login count exceeded", status_code=403)
+
+    if successful:
+        user.current_session_id = str(uuid.uuid4())
+        user.logged_in_at = datetime.utcnow()
+        user.failed_login_count = 0
+        save_model_user(user)
+    else:
+        increment_failed_login_count(user)
+
+    return jsonify({}), 204
+
+
 @user_blueprint.route('/<uuid:user_id>/<code_type>-code', methods=['POST'])
 def send_user_2fa_code(user_id, code_type):
     user_to_send_to = get_user_by_id(user_id=user_id)
diff --git a/app/user/users_schema.py b/app/user/users_schema.py
index a8621c1ab..5ca9b9bf0 100644
--- a/app/user/users_schema.py
+++ b/app/user/users_schema.py
@@ -11,6 +11,18 @@ post_verify_code_schema = {
 }
 
 
+post_verify_webauthn_schema = {
+    '$schema': 'http://json-schema.org/draft-04/schema#',
+    'description': 'POST schema for verifying a webauthn login attempt',
+    'type': 'object',
+    'properties': {
+        'successful': {'type': 'boolean'}
+    },
+    'required': ['successful'],
+    'additionalProperties': False
+}
+
+
 post_send_user_email_code_schema = {
     '$schema': 'http://json-schema.org/draft-04/schema#',
     'description': (
diff --git a/tests/app/user/test_rest.py b/tests/app/user/test_rest.py
index a6f4dd55a..15b15c734 100644
--- a/tests/app/user/test_rest.py
+++ b/tests/app/user/test_rest.py
@@ -1,6 +1,6 @@
 import json
+import uuid
 from datetime import datetime
-from uuid import UUID
 
 import mock
 import pytest
@@ -278,7 +278,7 @@ def test_post_user_attribute(client, sample_user, user_attribute, user_value):
         },
         recipient='newuser@mail.com', reply_to_text='notify@gov.uk',
         service=mock.ANY,
-        template_id=UUID('c73f1d71-4049-46d5-a647-d013bdeca3f0'), template_version=1
+        template_id=uuid.UUID('c73f1d71-4049-46d5-a647-d013bdeca3f0'), template_version=1
     )),
     ('mobile_number', '+4407700900460', dict(
         api_key_id=None, key_type='normal', notification_type='sms',
@@ -287,7 +287,7 @@ def test_post_user_attribute(client, sample_user, user_attribute, user_value):
             'email address': 'notify@digital.cabinet-office.gov.uk'
         },
         recipient='+4407700900460', reply_to_text='testing', service=mock.ANY,
-        template_id=UUID('8a31520f-4751-4789-8ea1-fe54496725eb'), template_version=1
+        template_id=uuid.UUID('8a31520f-4751-4789-8ea1-fe54496725eb'), template_version=1
     ))
 ])
 def test_post_user_attribute_with_updated_by(
@@ -1149,3 +1149,68 @@ def test_get_sms_reply_to_for_notify_service(team_member_mobile_edit_template, n
     reply_to = get_sms_reply_to_for_notify_service(number, team_member_mobile_edit_template)
     assert reply_to == current_app.config['NOTIFY_INTERNATIONAL_SMS_SENDER'] \
         if expected_reply_to == 'notify_international_sender' else current_app.config['FROM_NUMBER']
+
+
+@freeze_time('2020-01-01 11:00')
+def test_verify_webauthn_login_resets_login_if_succesful(admin_request, sample_user):
+    sample_user.failed_login_count = 1
+
+    assert sample_user.current_session_id is None
+    assert sample_user.logged_in_at is None
+
+    admin_request.post(
+        'user.verify_webauthn_login_for_user',
+        user_id=sample_user.id,
+        _data={'successful': True},
+        _expected_status=204
+    )
+
+    assert sample_user.current_session_id is not None
+    assert sample_user.failed_login_count == 0
+    assert sample_user.logged_in_at == datetime(2020, 1, 1, 11, 0)
+
+
+def test_verify_webauthn_login_returns_204_when_not_successful(admin_request, sample_user):
+    # when unsuccessful this endpoint is used to bump the failed count. the endpoint still worked
+    # properly so should return 204 (no content).
+    sample_user.failed_login_count = 1
+
+    assert sample_user.current_session_id is None
+    assert sample_user.logged_in_at is None
+
+    admin_request.post(
+        'user.verify_webauthn_login_for_user',
+        user_id=sample_user.id,
+        _data={'successful': False},
+        _expected_status=204
+    )
+
+    assert sample_user.current_session_id is None
+    assert sample_user.failed_login_count == 2
+    assert sample_user.logged_in_at is None
+
+
+def test_verify_webauthn_login_raises_403_if_max_login_count_exceeded(admin_request, sample_user):
+    # when unsuccessful this endpoint is used to bump the failed count. the endpoint still worked
+    # properly so should return 204 (no content).
+    sample_user.failed_login_count = 10
+
+    admin_request.post(
+        'user.verify_webauthn_login_for_user',
+        user_id=sample_user.id,
+        _data={'successful': True},
+        _expected_status=403
+    )
+
+    assert sample_user.current_session_id is None
+    assert sample_user.failed_login_count == 10
+    assert sample_user.logged_in_at is None
+
+
+def test_verify_webauthn_login_raises_400_if_schema_invalid(admin_request):
+    admin_request.post(
+        'user.verify_webauthn_login_for_user',
+        user_id=uuid.uuid4(),
+        _data={'successful': 'True'},
+        _expected_status=400
+    )