diff --git a/control_plane/src/pageserver.rs b/control_plane/src/pageserver.rs
index 6309494b71..6fc3c43842 100644
--- a/control_plane/src/pageserver.rs
+++ b/control_plane/src/pageserver.rs
@@ -370,6 +370,10 @@ impl PageServerNode {
                 .remove("evictions_low_residence_duration_metric_threshold")
                 .map(|x| x.to_string()),
         };
+
+        // If tenant ID was not specified, generate one
+        let new_tenant_id = new_tenant_id.unwrap_or(TenantId::generate());
+
         let request = models::TenantCreateRequest {
             new_tenant_id,
             config,
diff --git a/libs/pageserver_api/src/models.rs b/libs/pageserver_api/src/models.rs
index 3bfedd14ea..9e3d7af351 100644
--- a/libs/pageserver_api/src/models.rs
+++ b/libs/pageserver_api/src/models.rs
@@ -131,12 +131,11 @@ pub struct TimelineCreateRequest {
 }
 
 #[serde_as]
-#[derive(Serialize, Deserialize, Debug, Default)]
+#[derive(Serialize, Deserialize, Debug)]
 #[serde(deny_unknown_fields)]
 pub struct TenantCreateRequest {
-    #[serde(default)]
-    #[serde_as(as = "Option<DisplayFromStr>")]
-    pub new_tenant_id: Option<TenantId>,
+    #[serde_as(as = "DisplayFromStr")]
+    pub new_tenant_id: TenantId,
     #[serde(flatten)]
     pub config: TenantConfig, // as we have a flattened field, we should reject all unknown fields in it
 }
@@ -184,10 +183,10 @@ pub struct StatusResponse {
 }
 
 impl TenantCreateRequest {
-    pub fn new(new_tenant_id: Option<TenantId>) -> TenantCreateRequest {
+    pub fn new(new_tenant_id: TenantId) -> TenantCreateRequest {
         TenantCreateRequest {
             new_tenant_id,
-            ..Default::default()
+            config: TenantConfig::default(),
         }
     }
 }
diff --git a/pageserver/src/http/openapi_spec.yml b/pageserver/src/http/openapi_spec.yml
index 0d09603650..f62828be21 100644
--- a/pageserver/src/http/openapi_spec.yml
+++ b/pageserver/src/http/openapi_spec.yml
@@ -918,6 +918,8 @@ components:
       allOf:
         - $ref: '#/components/schemas/TenantConfig'
         - type: object
+          required:
+            - new_tenant_id
           properties:
             new_tenant_id:
               type: string
diff --git a/pageserver/src/http/routes.rs b/pageserver/src/http/routes.rs
index 7d60d3568a..efe0896689 100644
--- a/pageserver/src/http/routes.rs
+++ b/pageserver/src/http/routes.rs
@@ -715,6 +715,8 @@ pub fn html_response(status: StatusCode, data: String) -> Result<Response<Body>,
 }
 
 async fn tenant_create_handler(mut request: Request<Body>) -> Result<Response<Body>, ApiError> {
+    let request_data: TenantCreateRequest = json_request(&mut request).await?;
+    let target_tenant_id = request_data.new_tenant_id;
     check_permission(&request, None)?;
 
     let _timer = STORAGE_TIME_GLOBAL
@@ -722,17 +724,10 @@ async fn tenant_create_handler(mut request: Request<Body>) -> Result<Response<Bo
         .expect("bug")
         .start_timer();
 
-    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Warn);
-
-    let request_data: TenantCreateRequest = json_request(&mut request).await?;
-
     let tenant_conf =
         TenantConfOpt::try_from(&request_data.config).map_err(ApiError::BadRequest)?;
 
-    let target_tenant_id = request_data
-        .new_tenant_id
-        .map(TenantId::from)
-        .unwrap_or_else(TenantId::generate);
+    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Warn);
 
     let state = get_state(&request);
 
diff --git a/test_runner/fixtures/pageserver/http.py b/test_runner/fixtures/pageserver/http.py
index 1349923cc4..2b8271958f 100644
--- a/test_runner/fixtures/pageserver/http.py
+++ b/test_runner/fixtures/pageserver/http.py
@@ -150,7 +150,7 @@ class PageserverHttpClient(requests.Session):
         return res_json
 
     def tenant_create(
-        self, new_tenant_id: Optional[TenantId] = None, conf: Optional[Dict[str, Any]] = None
+        self, new_tenant_id: TenantId, conf: Optional[Dict[str, Any]] = None
     ) -> TenantId:
         if conf is not None:
             assert "new_tenant_id" not in conf.keys()
diff --git a/test_runner/regress/test_auth.py b/test_runner/regress/test_auth.py
index 3e4a0bfbbb..c6cc54c869 100644
--- a/test_runner/regress/test_auth.py
+++ b/test_runner/regress/test_auth.py
@@ -53,14 +53,14 @@ def test_pageserver_auth(neon_env_builder: NeonEnvBuilder):
         )
 
     # create tenant using management token
-    pageserver_http_client.tenant_create()
+    pageserver_http_client.tenant_create(TenantId.generate())
 
     # fail to create tenant using tenant token
     with pytest.raises(
         PageserverApiException,
         match="Forbidden: Attempt to access management api with tenant scope. Permission denied",
     ):
-        tenant_http_client.tenant_create()
+        tenant_http_client.tenant_create(TenantId.generate())
 
 
 def test_compute_auth_to_pageserver(neon_env_builder: NeonEnvBuilder):
diff --git a/test_runner/regress/test_tenants.py b/test_runner/regress/test_tenants.py
index 5642449ce6..6599fa7ba5 100644
--- a/test_runner/regress/test_tenants.py
+++ b/test_runner/regress/test_tenants.py
@@ -314,21 +314,22 @@ def test_pageserver_with_empty_tenants(
 
     client = env.pageserver.http_client()
 
-    tenant_with_empty_timelines_dir = client.tenant_create()
-    temp_timelines = client.timeline_list(tenant_with_empty_timelines_dir)
+    tenant_with_empty_timelines = TenantId.generate()
+    client.tenant_create(tenant_with_empty_timelines)
+    temp_timelines = client.timeline_list(tenant_with_empty_timelines)
     for temp_timeline in temp_timelines:
         client.timeline_delete(
-            tenant_with_empty_timelines_dir, TimelineId(temp_timeline["timeline_id"])
+            tenant_with_empty_timelines, TimelineId(temp_timeline["timeline_id"])
         )
     files_in_timelines_dir = sum(
         1
         for _p in Path.iterdir(
-            Path(env.repo_dir) / "tenants" / str(tenant_with_empty_timelines_dir) / "timelines"
+            Path(env.repo_dir) / "tenants" / str(tenant_with_empty_timelines) / "timelines"
         )
     )
     assert (
         files_in_timelines_dir == 0
-    ), f"Tenant {tenant_with_empty_timelines_dir} should have an empty timelines/ directory"
+    ), f"Tenant {tenant_with_empty_timelines} should have an empty timelines/ directory"
 
     # Trigger timeline re-initialization after pageserver restart
     env.endpoints.stop_all()
@@ -356,15 +357,15 @@ def test_pageserver_with_empty_tenants(
 
     assert env.pageserver.log_contains(".*Setting tenant as Broken state, reason:.*")
 
-    [loaded_tenant] = [t for t in tenants if t["id"] == str(tenant_with_empty_timelines_dir)]
+    [loaded_tenant] = [t for t in tenants if t["id"] == str(tenant_with_empty_timelines)]
     assert (
         loaded_tenant["state"]["slug"] == "Active"
-    ), "Tenant {tenant_with_empty_timelines_dir} with empty timelines dir should be active and ready for timeline creation"
+    ), "Tenant {tenant_with_empty_timelines} with empty timelines dir should be active and ready for timeline creation"
 
-    loaded_tenant_status = client.tenant_status(tenant_with_empty_timelines_dir)
+    loaded_tenant_status = client.tenant_status(tenant_with_empty_timelines)
     assert (
         loaded_tenant_status["state"]["slug"] == "Active"
-    ), f"Tenant {tenant_with_empty_timelines_dir} without timelines dir should be active"
+    ), f"Tenant {tenant_with_empty_timelines} without timelines dir should be active"
 
     time.sleep(1)  # to allow metrics propagation
 
@@ -374,7 +375,7 @@ def test_pageserver_with_empty_tenants(
         "state": "Broken",
     }
     active_tenants_metric_filter = {
-        "tenant_id": str(tenant_with_empty_timelines_dir),
+        "tenant_id": str(tenant_with_empty_timelines),
         "state": "Active",
     }
 
@@ -386,7 +387,7 @@ def test_pageserver_with_empty_tenants(
 
     assert (
         tenant_active_count == 1
-    ), f"Tenant {tenant_with_empty_timelines_dir} should have metric as active"
+    ), f"Tenant {tenant_with_empty_timelines} should have metric as active"
 
     tenant_broken_count = int(
         ps_metrics.query_one(