diff --git a/src/eHerkenningUserDataInterface.php b/src/eHerkenningUserDataInterface.php
index 9f4508f..1c6d293 100644
--- a/src/eHerkenningUserDataInterface.php
+++ b/src/eHerkenningUserDataInterface.php
@@ -7,4 +7,10 @@
 interface eHerkenningUserDataInterface extends UserDataInterface
 {
     public function getKvk(): string;
+
+    public function getBsn(): ?string;
+
+    public function getRsin(): ?string;
+
+    public function getVestigingsnummer(): ?string;
 }