diff --git a/itou/eligibility/tasks.py b/itou/eligibility/tasks.py
index 7a32d81b35..5835a2c3eb 100644
--- a/itou/eligibility/tasks.py
+++ b/itou/eligibility/tasks.py
@@ -1,3 +1,4 @@
+import datetime
 import logging
 from json import JSONDecodeError
 
@@ -77,8 +78,11 @@ def certify_criteria(eligibility_diagnosis):
                     criterion.certified_at = timezone.now()
                     criterion.data_returned_by_api = data["raw_response"]
                     criterion.certification_period = None
-                    start_at, end_at = data["start_at"], data["end_at"]
-                    if start_at and end_at:
+                    if criterion.certified:
+                        start_at = data["start_at"]
+                        end_at = timezone.localdate(criterion.certified_at) + datetime.timedelta(
+                            days=criterion.CERTIFICATION_GRACE_PERIOD_DAYS
+                        )
                         criterion.certification_period = InclusiveDateRange(start_at, end_at)
     SelectedAdministrativeCriteria.objects.bulk_update(
         criteria,
diff --git a/itou/utils/apis/api_particulier.py b/itou/utils/apis/api_particulier.py
index 0a66967cb2..a06bd045c4 100644
--- a/itou/utils/apis/api_particulier.py
+++ b/itou/utils/apis/api_particulier.py
@@ -15,12 +15,6 @@ def client():
     )
 
 
-def _parse_date(date: str) -> datetime.date | None:
-    if date:
-        return datetime.date.fromisoformat(date)
-    return None
-
-
 def _build_params_from(job_seeker):
     jobseeker_profile = job_seeker.jobseeker_profile
     params = {
@@ -58,9 +52,10 @@ def has_required_info(job_seeker):
 
 def revenu_solidarite_active(client, job_seeker):
     response = _request(client, "/v2/revenu-solidarite-active", job_seeker)
+    certified = response["status"] == "beneficiaire"
     return {
-        "start_at": _parse_date(response["dateDebut"]),
-        "end_at": _parse_date(response["dateFin"]),
-        "is_certified": response["status"] == "beneficiaire",
+        "start_at": datetime.date.fromisoformat(response["dateDebut"]) if certified else None,
+        # Do not expose end_at, it’s always null.
+        "is_certified": certified,
         "raw_response": response,
     }
diff --git a/itou/utils/mocks/api_particulier.py b/itou/utils/mocks/api_particulier.py
index e295c574fe..0397af369f 100644
--- a/itou/utils/mocks/api_particulier.py
+++ b/itou/utils/mocks/api_particulier.py
@@ -1,6 +1,6 @@
 def rsa_certified_mocker():
     # https://github.com/etalab/siade_staging_data/blob/develop/payloads/api_particulier_v2_cnav_revenu_solidarite_active/200_beneficiaire_majoration.yaml
-    return {"status": "beneficiaire", "majoration": True, "dateDebut": "2024-08-01", "dateFin": "2024-10-31"}
+    return {"status": "beneficiaire", "majoration": True, "dateDebut": "2024-08-01", "dateFin": None}
 
 
 def rsa_not_certified_mocker():
diff --git a/tests/eligibility/test_iae.py b/tests/eligibility/test_iae.py
index d52d24bba5..4db20b98d8 100644
--- a/tests/eligibility/test_iae.py
+++ b/tests/eligibility/test_iae.py
@@ -557,7 +557,7 @@ def test_eligibility_diagnosis_certify_criteria(mocker, EligibilityDiagnosisFact
     assert criterion.certified is True
     assert criterion.certified_at == timezone.now()
     assert criterion.data_returned_by_api == rsa_certified_mocker()
-    assert criterion.certification_period == InclusiveDateRange(datetime.date(2024, 8, 1), datetime.date(2024, 10, 31))
+    assert criterion.certification_period == InclusiveDateRange(datetime.date(2024, 8, 1), datetime.date(2024, 12, 13))
 
 
 @pytest.mark.parametrize(
@@ -589,7 +589,7 @@ def test_eligibility_diagnosis_certify_criteria_missing_info(respx_mock, Eligibi
         pytest.param(
             partial(IAEEligibilityDiagnosisFactory, from_employer=True),
             {
-                "certification_period": InclusiveDateRange(datetime.date(2024, 8, 1), datetime.date(2024, 10, 31)),
+                "certification_period": InclusiveDateRange(datetime.date(2024, 8, 1), datetime.date(2024, 12, 13)),
                 "certified": True,
                 "certified_at": datetime.datetime(2024, 9, 12, tzinfo=datetime.UTC),
                 "data_returned_by_api": rsa_certified_mocker(),
@@ -601,7 +601,7 @@ def test_eligibility_diagnosis_certify_criteria_missing_info(respx_mock, Eligibi
         pytest.param(
             partial(GEIQEligibilityDiagnosisFactory, from_geiq=True),
             {
-                "certification_period": InclusiveDateRange(datetime.date(2024, 8, 1), datetime.date(2024, 10, 31)),
+                "certification_period": InclusiveDateRange(datetime.date(2024, 8, 1), datetime.date(2024, 12, 13)),
                 "certified": True,
                 "certified_at": datetime.datetime(2024, 9, 12, tzinfo=datetime.UTC),
                 "data_returned_by_api": rsa_certified_mocker(),
diff --git a/tests/eligibility/test_tasks.py b/tests/eligibility/test_tasks.py
index 7efaec5232..75c5eeac14 100644
--- a/tests/eligibility/test_tasks.py
+++ b/tests/eligibility/test_tasks.py
@@ -36,6 +36,7 @@ def geiq_eligibility_factory():
     ],
 )
 class TestCertifyCriteria:
+    @freeze_time("2025-01-06")
     def test_queue_task(self, factory, respx_mock):
         eligibility_diagnosis = factory()
         respx_mock.get(f"{settings.API_PARTICULIER_BASE_URL}v2/revenu-solidarite-active").respond(
@@ -54,7 +55,7 @@ def test_queue_task(self, factory, respx_mock):
         assert criterion.certified_at is not None
         assert criterion.data_returned_by_api == rsa_certified_mocker()
         assert criterion.certification_period == InclusiveDateRange(
-            datetime.date(2024, 8, 1), datetime.date(2024, 10, 31)
+            datetime.date(2024, 8, 1), datetime.date(2025, 4, 8)
         )
 
     def test_retry_task_rate_limits(self, factory, respx_mock):
diff --git a/tests/www/apply/test_process.py b/tests/www/apply/test_process.py
index 1971fdbdd6..cd66128c7f 100644
--- a/tests/www/apply/test_process.py
+++ b/tests/www/apply/test_process.py
@@ -2569,7 +2569,7 @@ def test_accept_iae__criteria_can_be_certified(self, client, mocker):
             assert criterion.certified
             assert criterion.data_returned_by_api == rsa_certified_mocker()
             assert criterion.certification_period == InclusiveDateRange(
-                datetime.date(2024, 8, 1), datetime.date(2024, 10, 31)
+                datetime.date(2024, 8, 1), datetime.date(2024, 12, 12)
             )
             assert criterion.certified_at
 
@@ -2634,7 +2634,7 @@ def test_accept_geiq__criteria_can_be_certified(self, client, mocker):
             assert criterion.certified
             assert criterion.data_returned_by_api == rsa_certified_mocker()
             assert criterion.certification_period == InclusiveDateRange(
-                datetime.date(2024, 8, 1), datetime.date(2024, 10, 31)
+                datetime.date(2024, 8, 1), datetime.date(2024, 12, 12)
             )
             assert criterion.certified_at