diff --git a/search-service/src/main/kotlin/com/egm/stellio/search/authorization/SubjectReferentialService.kt b/search-service/src/main/kotlin/com/egm/stellio/search/authorization/SubjectReferentialService.kt
index 8f53e719a..ba9bbc8dc 100644
--- a/search-service/src/main/kotlin/com/egm/stellio/search/authorization/SubjectReferentialService.kt
+++ b/search-service/src/main/kotlin/com/egm/stellio/search/authorization/SubjectReferentialService.kt
@@ -39,6 +39,23 @@ class SubjectReferentialService(
             .bind("groups_memberships", subjectReferential.groupsMemberships?.toTypedArray())
             .execute()
 
+    @Transactional
+    suspend fun upsertClient(subjectReferential: SubjectReferential): Either<APIException, Unit> =
+        databaseClient
+            .sql(
+                """
+                INSERT INTO subject_referential
+                    (subject_id, subject_type, subject_info)
+                    VALUES (:subject_id, :subject_type, :subject_info)
+                ON CONFLICT (subject_id)
+                    DO UPDATE SET subject_info = :subject_info
+                """.trimIndent()
+            )
+            .bind("subject_id", subjectReferential.subjectId)
+            .bind("subject_type", subjectReferential.subjectType.toString())
+            .bind("subject_info", subjectReferential.subjectInfo)
+            .execute()
+
     suspend fun retrieve(sub: Sub): Either<APIException, SubjectReferential> =
         databaseClient
             .sql(
diff --git a/search-service/src/main/kotlin/com/egm/stellio/search/listener/IAMListener.kt b/search-service/src/main/kotlin/com/egm/stellio/search/listener/IAMListener.kt
index 348c85ba6..ad68c4960 100644
--- a/search-service/src/main/kotlin/com/egm/stellio/search/listener/IAMListener.kt
+++ b/search-service/src/main/kotlin/com/egm/stellio/search/listener/IAMListener.kt
@@ -77,6 +77,7 @@ class IAMListener(
         tenantName: String,
         entityCreateEvent: EntityCreateEvent
     ): Either<APIException, Unit> = either {
+        val subjectType = SubjectType.valueOf(entityCreateEvent.entityTypes.first().uppercase())
         val operationPayload = entityCreateEvent.operationPayload.deserializeAsMap()
         val subjectInfo = operationPayload
             .filter { !JSONLD_COMPACTED_ENTITY_CORE_MEMBERS.contains(it.key) }
@@ -84,13 +85,16 @@ class IAMListener(
         val roles = extractRoles(operationPayload)
         val subjectReferential = SubjectReferential(
             subjectId = entityCreateEvent.entityId.extractSub(),
-            subjectType = SubjectType.valueOf(entityCreateEvent.entityTypes.first().uppercase()),
+            subjectType = subjectType,
             subjectInfo = Json.of(subjectInfo),
             globalRoles = roles
         )
 
         mono {
-            subjectReferentialService.create(subjectReferential)
+            if (subjectType == SubjectType.CLIENT)
+                subjectReferentialService.upsertClient(subjectReferential)
+            else
+                subjectReferentialService.create(subjectReferential)
         }.writeContextAndSubscribe(tenantName, entityCreateEvent)
     }
 
diff --git a/search-service/src/test/kotlin/com/egm/stellio/search/authorization/SubjectReferentialServiceTests.kt b/search-service/src/test/kotlin/com/egm/stellio/search/authorization/SubjectReferentialServiceTests.kt
index 4ce8b59a2..3fac48ba3 100644
--- a/search-service/src/test/kotlin/com/egm/stellio/search/authorization/SubjectReferentialServiceTests.kt
+++ b/search-service/src/test/kotlin/com/egm/stellio/search/authorization/SubjectReferentialServiceTests.kt
@@ -56,6 +56,43 @@ class SubjectReferentialServiceTests : WithTimescaleContainer {
             }, {})
     }
 
+    @Test
+    fun `it should persist a subject referential for a non-existing client`() = runTest {
+        val subjectReferential = SubjectReferential(
+            subjectId = serviceAccountUuid,
+            subjectType = SubjectType.CLIENT,
+            subjectInfo = getSubjectInfoForClient("client-id", "kc-id")
+        )
+
+        subjectReferentialService.create(subjectReferential)
+            .fold({
+                fail("it should have created a subject referential for the client")
+            }, {})
+    }
+
+    @Test
+    fun `it should upsert a subject referential for an existing client`() = runTest {
+        val subjectReferential = SubjectReferential(
+            subjectId = serviceAccountUuid,
+            subjectType = SubjectType.CLIENT,
+            subjectInfo = getSubjectInfoForClient("client-id-updated", "kc-id-updated")
+        )
+
+        subjectReferentialService.create(subjectReferential)
+            .fold({
+                fail("it should have created a subject referential for the client")
+            }, {})
+
+        subjectReferentialService.retrieve(serviceAccountUuid)
+            .shouldSucceedWith {
+                val subjectInfo = it.getSubjectInfoValue()
+                assertTrue(subjectInfo.containsKey("clientId"))
+                assertEquals("client-id-updated", subjectInfo["clientId"])
+                assertTrue(subjectInfo.containsKey("internalClientId"))
+                assertEquals("kc-id-updated", subjectInfo["internalClientId"])
+            }
+    }
+
     @Test
     fun `it should retrieve a subject referential`() = runTest {
         val subjectReferential = SubjectReferential(