diff --git a/src/DigiDPartnerSession.php b/src/DigiDPartnerSession.php
new file mode 100644
index 0000000..263bf27
--- /dev/null
+++ b/src/DigiDPartnerSession.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OWC\IdpUserData;
+
+class DigiDPartnerSession extends DigiDSession
+{
+    protected static function get_slot(): string
+    {
+        return '2';
+    }
+
+    public static function getUserData(): ?DigiDUserDataInterface
+    {
+        return parent::getUserData();
+    }
+}
diff --git a/src/IdpSession.php b/src/IdpSession.php
index 2d59e29..866e77c 100644
--- a/src/IdpSession.php
+++ b/src/IdpSession.php
@@ -8,17 +8,44 @@ abstract class IdpSession
 {
     abstract protected static function get_idp(): string;
 
+    /**
+     * Returns the session slot identifier.
+     * Empty string means the primary session and '2' means the partner/second login session.
+     */
+    protected static function get_slot(): string
+    {
+        return '';
+    }
+
+    public static function isPartnerSession(): bool
+    {
+        return static::get_slot() === '2';
+    }
+
+    public static function isPartnerLoggedIn(): bool
+    {
+        $isLoggedIn = apply_filters('owc_idp_is_logged_in', false, static::get_idp(), '2');
+
+        return apply_filters('owc_' . static::get_idp() . '_is_logged_in_2', $isLoggedIn);
+    }
+
     public static function isLoggedIn(): bool
     {
-        $isLoggedIn = apply_filters('owc_idp_is_logged_in', false, static::get_idp());
+        $slot         = static::get_slot();
+        $filterSuffix = $slot !== '' ? '_' . $slot : '';
+
+        $isLoggedIn = apply_filters('owc_idp_is_logged_in', false, static::get_idp(), $slot);
 
-        return apply_filters('owc_' . static::get_idp() . '_is_logged_in', $isLoggedIn);
+        return apply_filters('owc_' . static::get_idp() . '_is_logged_in' . $filterSuffix, $isLoggedIn);
     }
 
     protected static function getUserData(): ?UserDataInterface
     {
-        $userData = apply_filters('owc_idp_userdata', null, static::get_idp());
+        $slot         = static::get_slot();
+        $filterSuffix = $slot !== '' ? '_' . $slot : '';
+
+        $userData = apply_filters('owc_idp_userdata', null, static::get_idp(), $slot);
 
-        return apply_filters('owc_' . static::get_idp() . '_userdata', $userData);
+        return apply_filters('owc_' . static::get_idp() . '_userdata' . $filterSuffix, $userData);
     }
 }
diff --git a/src/eHerkenningPartnerSession.php b/src/eHerkenningPartnerSession.php
new file mode 100644
index 0000000..3f1ab29
--- /dev/null
+++ b/src/eHerkenningPartnerSession.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OWC\IdpUserData;
+
+class eHerkenningPartnerSession extends eHerkenningSession
+{
+    protected static function get_slot(): string
+    {
+        return '2';
+    }
+
+    public static function getUserData(): ?eHerkenningUserDataInterface
+    {
+        return parent::getUserData();
+    }
+}
diff --git a/src/eIDASPartnerSession.php b/src/eIDASPartnerSession.php
new file mode 100644
index 0000000..10712c4
--- /dev/null
+++ b/src/eIDASPartnerSession.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OWC\IdpUserData;
+
+class eIDASPartnerSession extends eIDASSession
+{
+    protected static function get_slot(): string
+    {
+        return '2';
+    }
+
+    public static function getUserData(): ?eIDASUserDataInterface
+    {
+        return parent::getUserData();
+    }
+}