diff --git a/extensions/data-plane/data-plane-signaling/data-plane-signaling-client/src/main/java/org/eclipse/edc/connector/dataplane/client/DataPlaneSignalingClient.java b/extensions/data-plane/data-plane-signaling/data-plane-signaling-client/src/main/java/org/eclipse/edc/connector/dataplane/client/DataPlaneSignalingClient.java
index aa0ca5a377d..49e2510f323 100644
--- a/extensions/data-plane/data-plane-signaling/data-plane-signaling-client/src/main/java/org/eclipse/edc/connector/dataplane/client/DataPlaneSignalingClient.java
+++ b/extensions/data-plane/data-plane-signaling/data-plane-signaling-client/src/main/java/org/eclipse/edc/connector/dataplane/client/DataPlaneSignalingClient.java
@@ -67,7 +67,9 @@ public DataPlaneSignalingClient(EdcHttpClient httpClient, TypeTransformerRegistr
     @WithSpan
     @Override
     public StatusResult<DataFlowResponseMessage> start(DataFlowStartMessage message) {
-        return send(message, dataPlane.getUrl().toString(), message.getProcessId(), this::handleStartResponse);
+        return Optional.ofNullable(dataPlane)
+                .map(instance -> send(message, instance.getUrl().toString(), message.getProcessId(), this::handleStartResponse))
+                .orElseGet(() -> StatusResult.failure(FATAL_ERROR, noDataPlaneInstanceFound(message)));
     }
 
     @Override
@@ -84,6 +86,13 @@ public StatusResult<Void> terminate(String transferProcessId) {
         return send(message, url, transferProcessId, r -> StatusResult.success());
     }
 
+    private String noDataPlaneInstanceFound(DataFlowStartMessage message) {
+        var source = message.getSourceDataAddress().getType();
+        var destination = message.getDestinationDataAddress().getType();
+        var processId = message.getProcessId();
+        return "Unable to process transfer %s: No data plane found for source: %s and destination: %s".formatted(processId, source, destination);
+    }
+
     private <T> StatusResult<T> send(Object message, String url, String processId, Function<Response, StatusResult<T>> handleStartResponse) {
         var requestBuilder = transformerRegistry.transform(message, JsonObject.class)
                 .compose(jsonLd::compact)
diff --git a/extensions/data-plane/data-plane-signaling/data-plane-signaling-client/src/test/java/org/eclipse/edc/connector/dataplane/client/DataPlaneSignalingClientTest.java b/extensions/data-plane/data-plane-signaling/data-plane-signaling-client/src/test/java/org/eclipse/edc/connector/dataplane/client/DataPlaneSignalingClientTest.java
index 6c3903ca1b2..11f2c0bf982 100644
--- a/extensions/data-plane/data-plane-signaling/data-plane-signaling-client/src/test/java/org/eclipse/edc/connector/dataplane/client/DataPlaneSignalingClientTest.java
+++ b/extensions/data-plane/data-plane-signaling/data-plane-signaling-client/src/test/java/org/eclipse/edc/connector/dataplane/client/DataPlaneSignalingClientTest.java
@@ -180,6 +180,7 @@ void start_verifyReturnFatalErrorIfTransformFails() {
                 );
     }
 
+
     @Test
     void start_verifyReturnFatalError_whenBadResponse() throws JsonProcessingException {
         var flowRequest = createDataFlowRequest();
@@ -203,6 +204,19 @@ void start_verifyReturnFatalError_whenBadResponse() throws JsonProcessingExcepti
                 );
     }
 
+    @Test
+    void start_verifyReturnFatalErrorWhenDataPlaneInstanceIsNull() {
+        var flowRequest = createDataFlowRequest();
+        TypeTransformerRegistry registry = mock();
+        var dataPlaneClient = new DataPlaneSignalingClient(testHttpClient(), registry, JSON_LD, MAPPER, null);
+
+        var result = dataPlaneClient.start(flowRequest);
+
+        assertThat(result.failed()).isTrue();
+        assertThat(result.getFailure().status()).isEqualTo(ResponseStatus.FATAL_ERROR);
+        assertThat(result.getFailureDetail()).contains("No data plane found for");
+    }
+
     @Test
     void start_verifyTransferSuccess() throws JsonProcessingException {
         var flowRequest = createDataFlowRequest();
@@ -252,48 +266,6 @@ void start_verifyTransferSuccess_withoutDataAddress() throws JsonProcessingExcep
         assertThat(result.getContent().getDataAddress()).isNull();
     }
 
-    @Nested
-    class Suspend {
-
-        @Test
-        void shouldCallSuspendOnAllTheAvailableDataPlanes() {
-            var httpRequest = new HttpRequest().withMethod("POST").withPath(DATA_PLANE_PATH + "/processId/suspend()");
-            dataPlane.when(httpRequest, once()).respond(response().withStatusCode(NO_CONTENT_204.code()));
-
-            var result = dataPlaneClient.suspend("processId");
-
-            assertThat(result).isSucceeded();
-            dataPlane.verify(httpRequest, VerificationTimes.once());
-        }
-
-        @Test
-        void shouldFail_whenConflictResponse() {
-            var httpRequest = new HttpRequest().withMethod("POST").withPath(DATA_PLANE_PATH + "/processId/suspend()");
-            dataPlane.when(httpRequest, once()).respond(response().withStatusCode(CONFLICT_409.code()));
-
-            var result = dataPlaneClient.suspend("processId");
-
-            assertThat(result).isFailed();
-        }
-
-        @Test
-        void verifyReturnFatalErrorIfTransformFails() {
-            TypeTransformerRegistry registry = mock();
-            var dataPlaneClient = new DataPlaneSignalingClient(testHttpClient(), registry, JSON_LD, MAPPER, instance);
-
-            when(registry.transform(any(), any())).thenReturn(Result.failure("Transform Failure"));
-
-            var result = dataPlaneClient.suspend("processId");
-
-            assertThat(result.failed()).isTrue();
-            assertThat(result.getFailure().status()).isEqualTo(ResponseStatus.FATAL_ERROR);
-            assertThat(result.getFailureMessages())
-                    .anySatisfy(s -> assertThat(s)
-                            .isEqualTo("Transform Failure")
-                    );
-        }
-    }
-
     @Test
     void terminate_shouldCallTerminateOnAllTheAvailableDataPlanes() {
         var httpRequest = new HttpRequest().withMethod("POST").withPath(DATA_PLANE_PATH + "/processId/terminate");
@@ -350,4 +322,46 @@ private DataFlowStartMessage createDataFlowRequest() {
                 .destinationDataAddress(DataAddress.Builder.newInstance().type("test").build())
                 .build();
     }
+
+    @Nested
+    class Suspend {
+
+        @Test
+        void shouldCallSuspendOnAllTheAvailableDataPlanes() {
+            var httpRequest = new HttpRequest().withMethod("POST").withPath(DATA_PLANE_PATH + "/processId/suspend()");
+            dataPlane.when(httpRequest, once()).respond(response().withStatusCode(NO_CONTENT_204.code()));
+
+            var result = dataPlaneClient.suspend("processId");
+
+            assertThat(result).isSucceeded();
+            dataPlane.verify(httpRequest, VerificationTimes.once());
+        }
+
+        @Test
+        void shouldFail_whenConflictResponse() {
+            var httpRequest = new HttpRequest().withMethod("POST").withPath(DATA_PLANE_PATH + "/processId/suspend()");
+            dataPlane.when(httpRequest, once()).respond(response().withStatusCode(CONFLICT_409.code()));
+
+            var result = dataPlaneClient.suspend("processId");
+
+            assertThat(result).isFailed();
+        }
+
+        @Test
+        void verifyReturnFatalErrorIfTransformFails() {
+            TypeTransformerRegistry registry = mock();
+            var dataPlaneClient = new DataPlaneSignalingClient(testHttpClient(), registry, JSON_LD, MAPPER, instance);
+
+            when(registry.transform(any(), any())).thenReturn(Result.failure("Transform Failure"));
+
+            var result = dataPlaneClient.suspend("processId");
+
+            assertThat(result.failed()).isTrue();
+            assertThat(result.getFailure().status()).isEqualTo(ResponseStatus.FATAL_ERROR);
+            assertThat(result.getFailureMessages())
+                    .anySatisfy(s -> assertThat(s)
+                            .isEqualTo("Transform Failure")
+                    );
+        }
+    }
 }