diff --git a/app/Http/Controllers/BaseAPIController.php b/app/Http/Controllers/BaseAPIController.php
index 0718e95b91e4..4531afc2525e 100644
--- a/app/Http/Controllers/BaseAPIController.php
+++ b/app/Http/Controllers/BaseAPIController.php
@@ -61,40 +61,40 @@ class BaseAPIController extends Controller
         }
 
         $this->serializer = Request::get('serializer') ?: API_SERIALIZER_ARRAY;
-        
+
         if ($this->serializer === API_SERIALIZER_JSON) {
             $this->manager->setSerializer(new JsonApiSerializer());
         } else {
             $this->manager->setSerializer(new ArraySerializer());
         }
-        
+
         if (Utils::isNinjaDev()) {
             \DB::enableQueryLog();
         }
     }
 
     protected function handleAction($request)
-    { 
+    {
         $entity = $request->entity();
         $action = $request->action;
-        
+
         $repo = Utils::toCamelCase($this->entityType) . 'Repo';
-        
+
         $this->$repo->$action($entity);
-        
+
         return $this->itemResponse($entity);
     }
 
     protected function listResponse($query)
     {
         $transformerClass = EntityModel::getTransformerName($this->entityType);
-        $transformer = new $transformerClass(Auth::user()->account, Input::get('serializer'));        
+        $transformer = new $transformerClass(Auth::user()->account, Input::get('serializer'));
 
         $includes = $transformer->getDefaultIncludes();
         $includes = $this->getRequestIncludes($includes);
 
         $query->with($includes);
-        
+
         if ($updatedAt = Input::get('updated_at')) {
             $updatedAt = date('Y-m-d H:i:s', $updatedAt);
             $query->where(function($query) use ($includes, $updatedAt) {
@@ -106,14 +106,14 @@ class BaseAPIController extends Controller
                 }
             });
         }
-        
+
         if ($clientPublicId = Input::get('client_id')) {
             $filter = function($query) use ($clientPublicId) {
                 $query->where('public_id', '=', $clientPublicId);
             };
             $query->whereHas('client', $filter);
         }
-        
+
         if ( ! Utils::hasPermission('view_all')){
             if ($this->entityType == ENTITY_USER) {
                 $query->where('id', '=', Auth::user()->id);
@@ -121,7 +121,7 @@ class BaseAPIController extends Controller
                 $query->where('user_id', '=', Auth::user()->id);
             }
         }
-        
+
         $data = $this->createCollection($query, $transformer, $this->entityType);
 
         return $this->response($data);
@@ -130,10 +130,10 @@ class BaseAPIController extends Controller
     protected function itemResponse($item)
     {
         $transformerClass = EntityModel::getTransformerName($this->entityType);
-        $transformer = new $transformerClass(Auth::user()->account, Input::get('serializer'));        
+        $transformer = new $transformerClass(Auth::user()->account, Input::get('serializer'));
 
         $data = $this->createItem($item, $transformer, $this->entityType);
-        
+
         return $this->response($data);
     }
 
@@ -160,7 +160,7 @@ class BaseAPIController extends Controller
         } else {
             $resource = new Collection($query, $transformer, $entityType);
         }
-        
+
         return $this->manager->createData($resource)->toArray();
     }
 
@@ -171,7 +171,7 @@ class BaseAPIController extends Controller
             Log::info(Request::method() . ' - ' . Request::url() . ": $count queries");
             Log::info(json_encode(\DB::getQueryLog()));
         }
-        
+
         $index = Request::get('index') ?: 'data';
 
         if ($index == 'none') {
@@ -222,7 +222,18 @@ class BaseAPIController extends Controller
                 $data[] = $include;
             }
         }
-        
+
+        return $data;
+    }
+
+    protected function fileReponse($name, $data)
+    {
+        header('Content-Type: application/pdf');
+        header('Content-Length: ' . strlen($data));
+        header('Content-disposition: attachment; filename="' . $name . '"');
+        header('Cache-Control: public, must-revalidate, max-age=0');
+        header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');
+
         return $data;
     }
 }
diff --git a/app/Http/Controllers/InvoiceApiController.php b/app/Http/Controllers/InvoiceApiController.php
index 6d68573cdb42..a9b819cd1e0b 100644
--- a/app/Http/Controllers/InvoiceApiController.php
+++ b/app/Http/Controllers/InvoiceApiController.php
@@ -184,6 +184,10 @@ class InvoiceApiController extends BaseAPIController
                         ->with('client', 'invoice_items', 'invitations')
                         ->first();
 
+        if (isset($data['download_invoice']) && boolval($data['download_invoice'])) {
+            return $this->fileReponse($invoice->getFileName(), $invoice->getPDFString());
+        }
+
         return $this->itemResponse($invoice);
     }
 
@@ -361,14 +365,7 @@ class InvoiceApiController extends BaseAPIController
     public function download(InvoiceRequest $request)
     {
         $invoice = $request->entity();
-        $pdfString = $invoice->getPDFString();
 
-        header('Content-Type: application/pdf');
-        header('Content-Length: ' . strlen($pdfString));
-        header('Content-disposition: attachment; filename="' . $invoice->getFileName() . '"');
-        header('Cache-Control: public, must-revalidate, max-age=0');
-        header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');
-
-        return $pdfString;
+        return $this->fileReponse($invoice->getFileName(), $invoice->getPDFString());
     }
 }
diff --git a/app/Ninja/Transformers/PaymentTransformer.php b/app/Ninja/Transformers/PaymentTransformer.php
index c4e4328cb845..9f3ef3212863 100644
--- a/app/Ninja/Transformers/PaymentTransformer.php
+++ b/app/Ninja/Transformers/PaymentTransformer.php
@@ -29,7 +29,7 @@ class PaymentTransformer extends EntityTransformer
     public function __construct($account = null, $serializer = null, $invoice = null)
     {
         parent::__construct($account, $serializer);
-        
+
         $this->invoice = $invoice;
     }
 
@@ -57,6 +57,7 @@ class PaymentTransformer extends EntityTransformer
             'is_deleted' => (bool) $payment->is_deleted,
             'payment_type_id' => (int) $payment->payment_type_id,
             'invoice_id' => (int) ($this->invoice ? $this->invoice->public_id : $payment->invoice->public_id),
+            'invoice_number' => $this->invoice ? $this->invoice->invoice_number : $payment->invoice->invoice_number,
         ]);
     }
-}
\ No newline at end of file
+}