diff --git a/docs/source/spark/index.rst b/docs/source/spark/index.rst
index 84507f899..555a52fba 100644
--- a/docs/source/spark/index.rst
+++ b/docs/source/spark/index.rst
@@ -52,13 +52,28 @@ using ``num_executors`` and ``resources_per_executor``.
 
 .. note::
 
-   Batch job submission requires the ``spark-operator-spark`` ServiceAccount to
-   exist in the target namespace, with the required SparkApplication RBAC
-   permissions bound to it. Otherwise, ``submit_job()`` requests will fail.
-
-   This is a current Spark Operator requirement and is expected to be simplified
-   once `kubeflow/spark-operator#3049 <https://github.com/kubeflow/spark-operator/issues/3049>`_
-   is resolved.
+   ``SparkClient`` does not set a ServiceAccount on the driver spec. Both
+   interactive sessions and batch jobs need the driver to run as a
+   ServiceAccount with permission to create executor pods in the target
+   namespace. That ServiceAccount is provisioned and selected by the platform,
+   not by the SDK.
+
+   On a Kubeflow Platform install, the Profile controller creates a
+   ``default-editor`` ServiceAccount in every profile namespace and binds it to
+   the ``kubeflow-edit`` ClusterRole, which covers pods and services
+   in-namespace. Set ``controller.defaultServiceAccount=default-editor`` in the
+   Spark Operator Helm chart so the operator falls back to it. On a standalone
+   Spark Operator install, set it to a ServiceAccount that exists in every
+   namespace where you submit jobs — for example the ``<release>-spark``
+   account the chart creates in the namespaces listed under
+   ``spark.jobNamespaces``.
+
+   When ``controller.defaultServiceAccount`` is unset, the driver runs as the
+   namespace's ``default`` ServiceAccount and the job fails with a
+   ``403 Forbidden`` error when the driver tries to create executor pods.
+
+   Interactive sessions can override the ServiceAccount per session with
+   ``Driver(service_account=...)``; batch jobs have no per-job override.
 
 Two Ways to Run Spark
 -----------------------
diff --git a/examples/spark/README.md b/examples/spark/README.md
index fc605cd1a..e44fbcb75 100644
--- a/examples/spark/README.md
+++ b/examples/spark/README.md
@@ -35,7 +35,7 @@ Install spark dependencies:
 uv pip install kubeflow[spark]
 ```
 
-The Spark examples run against a Kubernetes cluster with the Spark Operator installed. Batch job submission requires a `spark-operator-spark` ServiceAccount in the target namespace with the required SparkApplication RBAC permissions. See the [Spark SDK docs](https://sdk.kubeflow.org/en/latest/spark/index.html) for prerequisites.
+The Spark examples run against a Kubernetes cluster with the Spark Operator installed. The SDK does not set a ServiceAccount on the driver spec, so the Spark Operator must be configured with a fallback ServiceAccount that can create executor pods in the target namespace (`controller.defaultServiceAccount` in the Helm chart). See the [Spark SDK docs](https://sdk.kubeflow.org/en/latest/spark/index.html) for prerequisites.
 
 ## Running Examples
 
diff --git a/kubeflow/spark/backends/kubernetes/constants.py b/kubeflow/spark/backends/kubernetes/constants.py
index dc4067246..3b78c0ae0 100644
--- a/kubeflow/spark/backends/kubernetes/constants.py
+++ b/kubeflow/spark/backends/kubernetes/constants.py
@@ -51,7 +51,6 @@
 DEFAULT_DRIVER_MEMORY = "512Mi"
 DEFAULT_EXECUTOR_CPU = 1
 DEFAULT_EXECUTOR_MEMORY = "512Mi"
-DEFAULT_SERVICE_ACCOUNT = "spark-operator-spark"
 
 # Function-based Spark job script
 FUNC_JOB_VOLUME_NAME = "spark-app-source"
diff --git a/kubeflow/spark/backends/kubernetes/utils.py b/kubeflow/spark/backends/kubernetes/utils.py
index 1885bce04..2deb91176 100644
--- a/kubeflow/spark/backends/kubernetes/utils.py
+++ b/kubeflow/spark/backends/kubernetes/utils.py
@@ -682,7 +682,6 @@ def get_spark_job_driver_spec(
     return models.SparkV1beta2DriverSpec(
         cores=cores,
         memory=memory,
-        service_account=constants.DEFAULT_SERVICE_ACCOUNT,
     )
 
 
diff --git a/kubeflow/spark/backends/kubernetes/utils_test.py b/kubeflow/spark/backends/kubernetes/utils_test.py
index 35170d3b7..c13672d9a 100644
--- a/kubeflow/spark/backends/kubernetes/utils_test.py
+++ b/kubeflow/spark/backends/kubernetes/utils_test.py
@@ -1245,7 +1245,7 @@ def test_read_pod_logs(test_case: TestCase) -> None:
     "test_case",
     [
         TestCase(
-            name="default spark job driver spec",
+            name="default spark job driver spec leaves service account unset",
             expected_status=SUCCESS,
             config={},
         ),
@@ -1264,7 +1264,7 @@ def test_get_spark_job_driver_spec(test_case: TestCase) -> None:
     assert spec.memory == _memory_kubernetes_to_spark(
         constants.DEFAULT_DRIVER_MEMORY,
     )
-    assert spec.service_account == constants.DEFAULT_SERVICE_ACCOUNT
+    assert spec.service_account is None
 
     print("test execution complete")