diff --git a/participation/tests.py b/participation/tests.py
index 70aaa78..00aecc0 100644
--- a/participation/tests.py
+++ b/participation/tests.py
@@ -6,7 +6,7 @@ from django.contrib.contenttypes.models import ContentType
 from django.contrib.sites.models import Site
 from django.core.files.uploadedfile import SimpleUploadedFile
 from django.core.management import call_command
-from django.test import TestCase
+from django.test import LiveServerTestCase, override_settings, TestCase
 from django.urls import reverse
 from registration.models import CoachRegistration, Payment, StudentRegistration
 
@@ -875,6 +875,208 @@ class TestPayment(TestCase):
         self.assertFalse(payment.valid)
 
 
+@override_settings(HELLOASSO_TEST_ENDPOINT=True, ROOT_URLCONF="tfjm.helloasso.test_urls")
+class TestHelloAssoPayment(LiveServerTestCase):
+    """
+    Tests that are relative to a HelloAsso
+    """
+
+    def setUp(self):
+        self.superuser = User.objects.create_superuser(
+            username="admin",
+            email="admin@example.com",
+            password="admin",
+        )
+        self.tournament = Tournament.objects.create(
+            name="France",
+            place="Here",
+            price=21,
+        )
+        self.team = Team.objects.create(
+            name="Super team",
+            trigram="AAA",
+            access_code="azerty",
+        )
+        self.user = User.objects.create(
+            first_name="Toto",
+            last_name="Toto",
+            email="toto@example.com",
+            password="toto",
+        )
+        StudentRegistration.objects.create(
+            user=self.user,
+            team=self.team,
+            student_class=12,
+            address="1 Rue de Rivoli",
+            zip_code=75001,
+            city="Paris",
+            school="Earth",
+            give_contact_to_animath=True,
+            email_confirmed=True,
+        )
+        self.coach = User.objects.create(
+            first_name="Coach",
+            last_name="Coach",
+            email="coach@example.com",
+            password="coach",
+        )
+        CoachRegistration.objects.create(
+            user=self.coach,
+            team=self.team,
+            address="1 Rue de Rivoli",
+            zip_code=75001,
+            city="Paris",
+        )
+
+        self.team.participation.tournament = self.tournament
+        self.team.participation.valid = True
+        self.team.participation.save()
+        self.client.force_login(self.user)
+
+        Site.objects.update(domain=self.live_server_url.replace("http://", ""))
+
+    def test_create_checkout_intent(self):
+        with self.settings(HELLOASSO_TEST_ENDPOINT_URL=self.live_server_url):
+            payment = Payment.objects.get(registrations=self.user.registration, final=False)
+            checkout_intent = payment.create_checkout_intent()
+
+            self.assertIsNotNone(checkout_intent)
+            self.assertEqual(checkout_intent['metadata'], {
+                'payment_id': payment.pk,
+                'users': [
+                    {
+                        'user_id': self.user.pk,
+                        'first_name': self.user.first_name,
+                        'last_name': self.user.last_name,
+                        'email': self.user.email,
+                    }
+                ],
+                'final': False,
+                'tournament_id': self.tournament.pk,
+            })
+            self.assertNotIn('order', checkout_intent)
+
+            checkout_intent_fetched = payment.get_checkout_intent()
+            self.assertEqual(checkout_intent, checkout_intent_fetched)
+
+            # Don't create a new checkout intent if one already exists
+            checkout_intent_new = payment.create_checkout_intent()
+            self.assertEqual(checkout_intent, checkout_intent_new)
+
+            payment.refresh_from_db()
+            self.assertEqual(payment.checkout_intent_id, checkout_intent['id'])
+            self.assertFalse(payment.valid)
+
+    def test_helloasso_payment_success(self):
+        """
+        Simulates the redirection to Hello Asso and the return for a successful payment.
+        """
+        with self.settings(HELLOASSO_TEST_ENDPOINT_URL=self.live_server_url):
+            payment = Payment.objects.get(registrations=self.user.registration, final=False)
+            self.assertIsNone(payment.checkout_intent_id)
+            self.assertFalse(payment.valid)
+
+            response = self.client.get(reverse('registration:update_payment', args=(payment.pk,)))
+            self.assertEqual(response.status_code, 200)
+
+            response = self.client.get(reverse('registration:payment_hello_asso', args=(payment.pk,)),
+                                       follow=True)
+            self.assertEqual(response.status_code, 200)
+            self.assertEqual(response.redirect_chain[-1],
+                             (reverse('participation:team_detail', args=(self.team.pk,)), 302))
+            self.assertIn("type=return", response.redirect_chain[1][0])
+            self.assertIn("code=succeeded", response.redirect_chain[1][0])
+
+            payment.refresh_from_db()
+            self.assertIsNotNone(payment.checkout_intent_id)
+            self.assertTrue(payment.valid)
+
+            checkout_intent = payment.get_checkout_intent()
+            self.assertIn('order', checkout_intent)
+
+    def test_helloasso_payment_refused(self):
+        """
+        Simulates the redirection to Hello Asso and the return for a refused payment.
+        """
+        with self.settings(HELLOASSO_TEST_ENDPOINT_URL=self.live_server_url):
+            payment = Payment.objects.get(registrations=self.user.registration, final=False)
+            checkout_intent = payment.create_checkout_intent()
+            self.assertFalse(payment.valid)
+
+            response = self.client.get(reverse('registration:update_payment', args=(payment.pk,)))
+            self.assertEqual(response.status_code, 200)
+
+            response = self.client.get(checkout_intent['redirectUrl'] + "?refused", follow=True)
+            self.assertEqual(response.status_code, 200)
+            self.assertEqual(response.redirect_chain[-1],
+                             (reverse('registration:update_payment', args=(payment.pk,)), 302))
+            self.assertIn("type=return", response.redirect_chain[0][0])
+            self.assertIn("code=refused", response.redirect_chain[0][0])
+
+            payment.refresh_from_db()
+            self.assertFalse(payment.valid)
+
+            checkout_intent = payment.get_checkout_intent()
+            self.assertNotIn('order', checkout_intent)
+
+    def test_helloasso_payment_error(self):
+        """
+        Simulates the redirection to Hello Asso and the return for an errored payment.
+        """
+        with self.settings(HELLOASSO_TEST_ENDPOINT_URL=self.live_server_url):
+            payment = Payment.objects.get(registrations=self.user.registration, final=False)
+            checkout_intent = payment.create_checkout_intent()
+            self.assertFalse(payment.valid)
+
+            response = self.client.get(reverse('registration:update_payment', args=(payment.pk,)))
+            self.assertEqual(response.status_code, 200)
+
+            response = self.client.get(checkout_intent['redirectUrl'] + "?error", follow=True)
+            self.assertEqual(response.status_code, 200)
+            self.assertEqual(response.redirect_chain[-1],
+                             (reverse('registration:update_payment', args=(payment.pk,)), 302))
+            self.assertIn("type=error", response.redirect_chain[0][0])
+            self.assertIn("error=", response.redirect_chain[0][0])
+
+            payment.refresh_from_db()
+            self.assertFalse(payment.valid)
+
+            checkout_intent = payment.get_checkout_intent()
+            self.assertNotIn('order', checkout_intent)
+
+    def test_anonymous_payment(self):
+        """
+        Test to make a successful payment from an anonymous user, authenticated by token.
+        """
+        self.client.logout()
+
+        with self.settings(HELLOASSO_TEST_ENDPOINT_URL=self.live_server_url):
+            payment = Payment.objects.get(registrations=self.user.registration, final=False)
+            self.assertIsNone(payment.checkout_intent_id)
+            self.assertFalse(payment.valid)
+
+            response = self.client.get(reverse('registration:payment_hello_asso', args=(payment.pk,)),
+                                       follow=True)
+            self.assertRedirects(response,
+                                 f"{reverse('login')}?next="
+                                 f"{reverse('registration:payment_hello_asso', args=(payment.pk,))}")
+
+            response = self.client.get(
+                reverse('registration:payment_hello_asso', args=(payment.pk,)) + "?token=" + payment.token,
+                follow=True)
+            self.assertEqual(response.status_code, 200)
+            self.assertEqual(response.redirect_chain[-1], (reverse('index'), 302))
+            self.assertIn("type=return", response.redirect_chain[1][0])
+            self.assertIn("code=succeeded", response.redirect_chain[1][0])
+
+            payment.refresh_from_db()
+            self.assertIsNotNone(payment.checkout_intent_id)
+            self.assertTrue(payment.valid)
+
+            checkout_intent = payment.get_checkout_intent()
+            self.assertIn('order', checkout_intent)
+
+
 class TestAdmin(TestCase):
     def setUp(self) -> None:
         self.user = User.objects.create_superuser(
diff --git a/tfjm/helloasso/__init__.py b/tfjm/helloasso/__init__.py
index de41fb8..0b3139d 100644
--- a/tfjm/helloasso/__init__.py
+++ b/tfjm/helloasso/__init__.py
@@ -13,7 +13,7 @@ _expires_at = None
 
 def _get_hello_asso_api_base_url():
     if settings.HELLOASSO_TEST_ENDPOINT:
-        return f"{settings.HELLOASSO_TEST_ENDPOINT_URL}/helloasso-test"
+        return f"{settings.HELLOASSO_TEST_ENDPOINT_URL}/helloasso-test/api"
     elif not settings.DEBUG:
         return "https://api.helloasso.com"
     else:
diff --git a/tfjm/helloasso/test_urls.py b/tfjm/helloasso/test_urls.py
new file mode 100644
index 0000000..dbcac4b
--- /dev/null
+++ b/tfjm/helloasso/test_urls.py
@@ -0,0 +1,23 @@
+# Copyright (C) 2024 by Animath
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from django.urls import path
+import tfjm.urls
+
+from . import test_views
+
+urlpatterns = tfjm.urls.urlpatterns
+
+urlpatterns += [
+    path('helloasso-test/api/oauth2/token', test_views.TestHelloAssoOAuth2View.as_view(),
+         name='helloasso-test-oauth2-token'),
+    path('helloasso-test/api/v5/organizations/animath/checkout-intents/',
+         test_views.TestHelloAssoCheckoutIntentCreateView.as_view(),
+         name='helloasso-test-checkout-intent-create'),
+    path('helloasso-test/api/v5/organizations/animath/checkout-intents/<int:checkout_intent_id>/',
+         test_views.TestHelloAssoCheckoutIntentDetailView.as_view(),
+         name='helloasso-test-checkout-intent-detail'),
+    path('helloasso-test/redirect-payment/<int:checkout_intent_id>/',
+         test_views.TestHelloAssoRedirectPaymentView.as_view(),
+         name='helloasso-test-redirect-payment'),
+]
diff --git a/tfjm/helloasso/test_views.py b/tfjm/helloasso/test_views.py
new file mode 100644
index 0000000..034653c
--- /dev/null
+++ b/tfjm/helloasso/test_views.py
@@ -0,0 +1,149 @@
+# Copyright (C) 2024 by Animath
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+import json
+
+from django.conf import settings
+from django.http import Http404, HttpResponse, JsonResponse
+from django.shortcuts import redirect
+from django.urls import reverse
+from django.utils import timezone
+from django.utils.decorators import method_decorator
+from django.views.decorators.csrf import csrf_exempt
+from django.views.generic.base import View
+
+_CHECKOUT_INTENTS = {}
+
+
+@method_decorator(csrf_exempt, name='dispatch')
+class TestHelloAssoOAuth2View(View):
+    def post(self, request, *args, **kwargs):
+        data = {
+            'access_token': 'test_access_token',
+            'refresh_token': 'test_refresh_token',
+            'expires_in': 3600,
+        }
+        return JsonResponse(data)
+
+
+@method_decorator(csrf_exempt, name='dispatch')
+class TestHelloAssoCheckoutIntentCreateView(View):
+    def post(self, request, *args, **kwargs):
+        checkout_intent_id = len(_CHECKOUT_INTENTS) + 1
+        body = json.loads(request.body.decode())
+
+        body['backUrl'] = body['backUrl'].replace("https", "http")
+        body['returnUrl'] = body['returnUrl'].replace("https", "http")
+        body['errorUrl'] = body['errorUrl'].replace("https", "http")
+
+        output_data = {
+            'id': checkout_intent_id,
+            'redirectUrl': f"{settings.HELLOASSO_TEST_ENDPOINT_URL}"
+                           f"{reverse('helloasso-test-redirect-payment', args=(checkout_intent_id,))}",
+            'metadata': body['metadata'],
+        }
+
+        checkout_intent = {'input': body, 'output': output_data}
+        _CHECKOUT_INTENTS[checkout_intent_id] = checkout_intent
+
+        return JsonResponse(output_data)
+
+
+class TestHelloAssoCheckoutIntentDetailView(View):
+    def get(self, request, *args, **kwargs):
+        checkout_intent_id = kwargs['checkout_intent_id']
+        if checkout_intent_id not in _CHECKOUT_INTENTS:
+            raise Http404
+        return JsonResponse(_CHECKOUT_INTENTS[checkout_intent_id]['output'])
+
+
+class TestHelloAssoRedirectPaymentView(View):
+    def get(self, request, *args, **kwargs):
+        checkout_intent_id = kwargs['checkout_intent_id']
+        if checkout_intent_id not in _CHECKOUT_INTENTS:
+            raise Http404
+
+        checkout_intent = _CHECKOUT_INTENTS[checkout_intent_id]
+        ci_input = checkout_intent['input']
+        ci_output = checkout_intent['output']
+
+        if 'error' in request.GET:
+            return redirect(ci_input['errorUrl'] + f"&checkoutIntentId={checkout_intent_id}&error=An error occurred.")
+        elif 'refused' in request.GET:
+            return redirect(ci_input['returnUrl'] + f"&checkoutIntentId={checkout_intent_id}&code=refused")
+
+        dt = timezone.now().isoformat()
+
+        ci_output['order'] = {
+            'payer': {
+                'email': 'payer@example.com',
+                'country': 'FRA',
+                'dateOfBirth': '2000-01-01T00:00:00+01:00',
+                'firstName': "Payer",
+                'lastName': "Payer",
+            },
+            'items': [
+                {
+                    'payments': [
+                        {
+                            'id': checkout_intent_id,
+                            'shareAmount': ci_input['totalAmount'],
+                        }
+                    ],
+                    'name': ci_input['itemName'],
+                    'priceCategory': 'Fixed',
+                    'qrCode': '',
+                    'id': checkout_intent_id,
+                    'amount': ci_input['totalAmount'],
+                    'type': 'Payment',
+                    'state': 'Processed'
+                }
+            ],
+            'payments': [
+                {
+                    'items': [
+                        {
+                            'id': checkout_intent_id,
+                            'shareAmount': ci_input['totalAmount'],
+                            'shareItemAmount': ci_input['totalAmount'],
+                        }
+                    ],
+                    'cashOutState': 'MoneyIn',
+                    'paymentReceiptUrl': "https://example.com/",
+                    'id': checkout_intent_id,
+                    'amount': ci_input['totalAmount'],
+                    'date': dt,
+                    'paymentMeans': 'Card',
+                    'installmentNumber': 1,
+                    'state': 'Authorized',
+                    'meta': {
+                        'createdAt': dt,
+                        'updatedAt': dt,
+                    },
+                    'refundOperations': []
+                }
+            ],
+            'amount': {
+                'total': ci_input['totalAmount'],
+                'vat': 0,
+                'discount': 0
+            },
+            'id': 13339,
+            'date': dt,
+            'formSlug': 'default',
+            'formType': 'Checkout',
+            'organizationName': 'Animath',
+            'organizationSlug': 'animath',
+            'checkoutIntentId': checkout_intent_id,
+            'meta': {
+                'createdAt': dt,
+                'updatedAt': dt,
+            },
+            'isAnonymous': False,
+            'isAmountHidden': False
+        }
+
+        return redirect(ci_input['returnUrl'] + f"&checkoutIntentId={checkout_intent_id}&code=succeeded")
+
+    def head(self, request, *args, **kwargs):
+        return HttpResponse()
diff --git a/tfjm/settings.py b/tfjm/settings.py
index f9a8767..b297970 100644
--- a/tfjm/settings.py
+++ b/tfjm/settings.py
@@ -244,6 +244,7 @@ PHONENUMBER_DEFAULT_REGION = 'FR'
 # Hello Asso API creds
 HELLOASSO_CLIENT_ID = os.getenv('HELLOASSO_CLIENT_ID', 'CHANGE_ME_IN_ENV_SETTINGS')
 HELLOASSO_CLIENT_SECRET = os.getenv('HELLOASSO_CLIENT_SECRET', 'CHANGE_ME_IN_ENV_SETTINGS')
+HELLOASSO_TEST_ENDPOINT = False  # Enable custom test endpoint, for unit tests
 
 # Custom parameters
 PROBLEMS = [