diff --git a/src/Helper/MyParcelCollection.php b/src/Helper/MyParcelCollection.php
index 9f47c9a2..eaaeed3f 100644
--- a/src/Helper/MyParcelCollection.php
+++ b/src/Helper/MyParcelCollection.php
@@ -269,15 +269,24 @@ public function createConcepts(): self
         $newConsignments = $this->where('consignment_id', '!=', null)->toArray();
         $this->addMissingReferenceId();
 
+        $grouped = $this->where('consignment_id', null)->groupBy(function(AbstractConsignment $item) {
+            return $item->getApiKey() . ($item->hasSender() ? '-sender' : '');
+        });
+
         /* @var MyParcelCollection $consignments */
-        foreach ($this->where('consignment_id', null)->groupBy('api_key') as $consignments) {
+        foreach ($grouped as $consignments) {
+            $headers = MyParcelRequest::HEADER_CONTENT_TYPE_SHIPMENT;
+            if ($consignments->first()->hasSender()) {
+                $headers += MyParcelRequest::HEADER_SET_CUSTOM_SENDER;
+            }
+
             $data    = (new CollectionEncode($consignments))->encode();
             $request = (new MyParcelRequest())
                 ->setUserAgents($this->getUserAgent())
                 ->setRequestParameters(
                     $consignments->first()->apiKey,
                     $data,
-                    MyParcelRequest::HEADER_CONTENT_TYPE_SHIPMENT
+                    $headers
                 )
                 ->sendRequest();
 
diff --git a/src/Model/Consignment/AbstractConsignment.php b/src/Model/Consignment/AbstractConsignment.php
index 7db65ed6..81f3be28 100755
--- a/src/Model/Consignment/AbstractConsignment.php
+++ b/src/Model/Consignment/AbstractConsignment.php
@@ -18,6 +18,7 @@
 use MyParcelNL\Sdk\src\Model\Carrier\AbstractCarrier;
 use MyParcelNL\Sdk\src\Model\Carrier\CarrierFactory;
 use MyParcelNL\Sdk\src\Model\MyParcelCustomsItem;
+use MyParcelNL\Sdk\src\Model\Recipient;
 use MyParcelNL\Sdk\src\Services\CountryCodes;
 use MyParcelNL\Sdk\src\Services\CountryService;
 use MyParcelNL\Sdk\src\Support\Str;
@@ -522,6 +523,11 @@ abstract class AbstractConsignment
      */
     private $state;
 
+    /**
+     * @var null|\MyParcelNL\Sdk\src\Model\Recipient
+     */
+    private $sender;
+
     /**
      * @throws \Exception
      */
@@ -532,6 +538,34 @@ public function __construct()
             : null;
     }
 
+    /**
+     * If you set a sender, a feature header will be added to the request.
+     * Exporting the consignment to MyParcel will throw an error if your shop (by apikey) does not have this permission.
+     *
+     * @param Recipient $sender
+     * @return $this
+     */
+    public function setSender(Recipient $sender): AbstractConsignment
+    {
+        $this->sender = $sender;
+
+        return $this;
+    }
+
+    public function hasSender(): bool
+    {
+        return isset($this->sender);
+    }
+
+    public function getSender(): ?Recipient
+    {
+        if (!$this->hasSender()) {
+            return null;
+        }
+
+        return $this->sender;
+    }
+
     /**
      * @return null|\MyParcelNL\Sdk\src\Model\Carrier\AbstractCarrier
      */
diff --git a/src/Model/MyParcelRequest.php b/src/Model/MyParcelRequest.php
index 3d4aac28..d6c14eac 100644
--- a/src/Model/MyParcelRequest.php
+++ b/src/Model/MyParcelRequest.php
@@ -40,6 +40,7 @@ class MyParcelRequest
         ];
     public const HEADER_ACCEPT_APPLICATION_PDF       = ['Accept' => 'application/pdf'];
     public const HEADER_CONTENT_TYPE_RETURN_SHIPMENT = ['Content-Type' => 'application/vnd.return_shipment+json; charset=utf-8'];
+    public const HEADER_SET_CUSTOM_SENDER            = ['x-dmp-set-custom-sender' => 'true'];
 
     /* @deprecated use HEADER_CONTENT_TYPE_SHIPMENT, HEADER_ACCEPT_APPLICATION_PDF or HEADER_CONTENT_TYPE_RETURN_SHIPMENT */
     public const REQUEST_HEADER_SHIPMENT = 'Content-Type: application/vnd.shipment+json;charset=utf-8;version=1.1';
diff --git a/src/Services/CollectionEncode.php b/src/Services/CollectionEncode.php
index 5bb794af..4ca17da5 100644
--- a/src/Services/CollectionEncode.php
+++ b/src/Services/CollectionEncode.php
@@ -55,10 +55,10 @@ private function groupMultiColloConsignments()
     {
         return $this->consignments->groupBy(function (AbstractConsignment $consignment) {
             if ($consignment->isPartOfMultiCollo()) {
-                return $consignment->getReferenceId();
+                return $consignment->getReferenceIdentifier();
             }
 
-            return 'random_to_prevent_multi_collo_' . uniqid();
+            return 'random_to_prevent_multi_collo_' . uniqid('', true);
         })->toArray();
     }
 }
diff --git a/src/Services/ConsignmentEncode.php b/src/Services/ConsignmentEncode.php
index be260021..6b9579ae 100644
--- a/src/Services/ConsignmentEncode.php
+++ b/src/Services/ConsignmentEncode.php
@@ -205,12 +205,17 @@ private function encodeBase(): self
             'carrier'   => $consignment->getCarrierId(),
         ];
 
-        if ($consignment->getReferenceId()) {
-            $this->consignmentEncoded['reference_identifier'] = $consignment->getReferenceId();
+
+        if (($sender = $consignment->getSender())) {
+            $this->consignmentEncoded['sender'] = $sender->toArrayWithoutNull();
+        }
+
+        if (($id = $consignment->getReferenceIdentifier())) {
+            $this->consignmentEncoded['reference_identifier'] = $id;
         }
 
-        if ($consignment->getCompany()) {
-            $this->consignmentEncoded['recipient']['company'] = $consignment->getCompany();
+        if (($company = $consignment->getCompany())) {
+            $this->consignmentEncoded['recipient']['company'] = $company;
         }
 
         return $this;