diff --git a/lib/Jejik/MT940/Transaction.php b/lib/Jejik/MT940/Transaction.php
index 4399c68..21abe3a 100644
--- a/lib/Jejik/MT940/Transaction.php
+++ b/lib/Jejik/MT940/Transaction.php
@@ -353,9 +353,10 @@ public function setEref(string $eref = null): TransactionInterface
     /**
      * Get BIC for this transaction
      */
-    public function getBIC(): string
+    public function getBIC(): ?string
     {
-        return trim($this->bic);
+        return ($this->bic !== null) ? trim($this->bic) : null;
+
     }
 
     /**
@@ -370,9 +371,9 @@ public function setBIC(string $bic = null): TransactionInterface
     /**
      * Get IBAN for this transaction
      */
-    public function getIBAN(): string
+    public function getIBAN(): ?string
     {
-        return trim($this->iban);
+        return ($this->iban !== null) ? trim($this->iban) : null;
     }
 
     /**