diff --git a/src/Message/CompletePurchaseRequest.php b/src/Message/CompletePurchaseRequest.php
index 210dfba..905eca0 100644
--- a/src/Message/CompletePurchaseRequest.php
+++ b/src/Message/CompletePurchaseRequest.php
@@ -258,7 +258,7 @@ public function getData()
             'key' => $this->getKey(),
             'prc' => $this->getPrc(),
             'finishtime' => $this->getFinishtime(),
-            'uid' => $this->getUid(),
+            'uid' => $this->getTransactionReference(),
             'order_id' => $this->getOrderId(),
             'user_id' => $this->getUserId(),
             'cost' => $this->getCost(),
diff --git a/src/Message/FetchTransactionRequest.php b/src/Message/FetchTransactionRequest.php
index 5887f59..6012444 100644
--- a/src/Message/FetchTransactionRequest.php
+++ b/src/Message/FetchTransactionRequest.php
@@ -13,9 +13,9 @@ class FetchTransactionRequest extends AbstractRequest
 
     public function getData()
     {
-        $this->validate('uid', 'key');
+        $this->validate('transactionReference', 'key');
 
-        return ['uid' => $this->getUid(), 'key' => $this->getKey()];
+        return ['uid' => $this->getTransactionReference(), 'key' => $this->getKey()];
     }
 
     protected function createBody(Encryption $encryption, array $data)
diff --git a/src/Message/RefundRequest.php b/src/Message/RefundRequest.php
index cd437ce..1df749c 100644
--- a/src/Message/RefundRequest.php
+++ b/src/Message/RefundRequest.php
@@ -39,11 +39,11 @@ public function getInvoiceState()
 
     public function getData()
     {
-        $this->validate('key', 'uid', 'amount');
+        $this->validate('key', 'transactionReference', 'amount');
 
         return [
             'key' => $this->getKey(),
-            'uid' => $this->getUid(),
+            'uid' => $this->getTransactionReference(),
             'cost' => $this->getAmount(),
             'invoice_state' => $this->getInvoiceState(),
         ];
diff --git a/src/Traits/HasUid.php b/src/Traits/HasUid.php
index 39dc0b6..55cd57a 100644
--- a/src/Traits/HasUid.php
+++ b/src/Traits/HasUid.php
@@ -12,7 +12,7 @@ trait HasUid
      */
     public function setUid($value)
     {
-        return $this->setParameter('uid', $value);
+        return $this->setTransactionReference($value);
     }
 
     /**
@@ -20,6 +20,6 @@ public function setUid($value)
      */
     public function getUid()
     {
-        return $this->getParameter('uid');
+        return $this->getTransactionReference();
     }
 }