diff --git a/public/typo3conf/ext/ep_theme/Classes/Form/AddReferrerFinisher.php b/public/typo3conf/ext/ep_theme/Classes/Form/AddReferrerFinisher.php
new file mode 100644
index 00000000..6f5463bd
--- /dev/null
+++ b/public/typo3conf/ext/ep_theme/Classes/Form/AddReferrerFinisher.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace EP\EpTheme\Form;
+
+use TYPO3\CMS\Form\Domain\Finishers\AbstractFinisher;
+
+class AddReferrerFinisher extends AbstractFinisher
+{
+    protected function executeInternal()
+    {
+        // Look for key 'referrer' in frontend session
+        $referrer = $GLOBALS['TSFE']->fe_user->getKey('ses', 'referrer');
+
+        if (null === $referrer) {
+            return;
+        }
+
+        // Add textfield to form containing referrer value
+        $field = $this->finisherContext
+            ->getFormRuntime()
+            ->getFormDefinition()
+            ->getPageByIndex(0)
+            ->createElement('referrer', 'Text');
+
+        $field->setDefaultValue($referrer);
+        $field->setDataType('string');
+        $field->setLabel('Referrer');
+
+        // Add finisher variable for potential later use
+        $this->finisherContext->getFinisherVariableProvider()->add(
+            $this->shortFinisherIdentifier,
+            'referrer',
+            $referrer
+        );
+
+        // Remove session key
+        $GLOBALS['TSFE']->fe_user->setKey('ses', 'referrer', null);
+        $GLOBALS['TSFE']->fe_user->storeSessionData();
+    }
+}
diff --git a/public/typo3conf/ext/ep_theme/Classes/Middleware/ReferrerMiddleware.php b/public/typo3conf/ext/ep_theme/Classes/Middleware/ReferrerMiddleware.php
new file mode 100644
index 00000000..35eed7a5
--- /dev/null
+++ b/public/typo3conf/ext/ep_theme/Classes/Middleware/ReferrerMiddleware.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace EP\EpTheme\Middleware;
+
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+use TYPO3\CMS\Core\Exception\SiteNotFoundException;
+use TYPO3\CMS\Core\Site\SiteFinder;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+class ReferrerMiddleware implements MiddlewareInterface
+{
+    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
+    {
+        $queryParams = $request->getQueryParams();
+
+        if (!array_key_exists('ref', $queryParams)) {
+            return $handler->handle($request);
+        }
+
+        $ref = $queryParams['ref'];
+
+        /** @var SiteFinder $siteFinder */
+        $siteFinder = GeneralUtility::makeInstance(SiteFinder::class);
+
+        try {
+            $site = $siteFinder->getSiteByPageId($ref);
+            $url = $site->getRouter()->generateUri($ref);
+            $GLOBALS['TSFE']->fe_user->setKey('ses', 'referrer', $url);
+            $GLOBALS['TSFE']->fe_user->storeSessionData();
+        }
+        catch (SiteNotFoundException $exception) {
+        }
+
+        return $handler->handle($request);
+    }
+}
diff --git a/public/typo3conf/ext/ep_theme/Configuration/RequestMiddlewares.php b/public/typo3conf/ext/ep_theme/Configuration/RequestMiddlewares.php
new file mode 100644
index 00000000..ec4ed8b7
--- /dev/null
+++ b/public/typo3conf/ext/ep_theme/Configuration/RequestMiddlewares.php
@@ -0,0 +1,12 @@
+<?php
+
+return [
+    'frontend' => [
+        'ep/referrer' => [
+            'target' => \EP\EpTheme\Middleware\ReferrerMiddleware::class,
+            'after' => [
+                'typo3/cms-frontend/site',
+            ],
+        ],
+    ],
+];
diff --git a/public/typo3conf/ext/ep_theme/Configuration/TypoScript/Extensions/Form.typoscript b/public/typo3conf/ext/ep_theme/Configuration/TypoScript/Extensions/Form.typoscript
index 7541f7a2..f0105ae1 100644
--- a/public/typo3conf/ext/ep_theme/Configuration/TypoScript/Extensions/Form.typoscript
+++ b/public/typo3conf/ext/ep_theme/Configuration/TypoScript/Extensions/Form.typoscript
@@ -6,9 +6,11 @@ plugin.tx_form.view {
 }
 
 plugin.tx_form.settings.yamlConfigurations {
-    100 = EXT:ep_theme/Configuration/Forms/FormSetup.yaml
+    1630994710 = EXT:ep_theme/Configuration/Yaml/FormsBase.yaml
+    1630994711 = EXT:ep_theme/Configuration/Yaml/FormFinishersFrontend.yaml
 }
 
 module.tx_form.settings.yamlConfigurations {
-    100 = EXT:ep_theme/Configuration/Forms/FormSetup.yaml
+    1630994710 = EXT:ep_theme/Configuration/Yaml/FormsBase.yaml
+    1630994711 = EXT:ep_theme/Configuration/Yaml/FormFinishersBackend.yaml
 }
diff --git a/public/typo3conf/ext/ep_theme/Configuration/Yaml/FormFinishersBackend.yaml b/public/typo3conf/ext/ep_theme/Configuration/Yaml/FormFinishersBackend.yaml
new file mode 100644
index 00000000..f155147c
--- /dev/null
+++ b/public/typo3conf/ext/ep_theme/Configuration/Yaml/FormFinishersBackend.yaml
@@ -0,0 +1,51 @@
+TYPO3:
+  CMS:
+    Form:
+      prototypes:
+        standard:
+          formElementsDefinition:
+            Form:
+              formEditor:
+                editors:
+                  900:
+                    selectOptions:
+                      1000:
+                        value: 'BpnApiFinisher'
+                        label: 'BusPro Finisher'
+                      1100:
+                        value: 'AddReferrerFinisher'
+                        label: 'Referrer Finisher'
+                propertyCollections:
+                  finishers:
+                    1000:
+                      identifier: 'BpnApiFinisher'
+                      editors:
+                        __inheritances:
+                          10: 'TYPO3.CMS.Form.mixins.formElementMixins.BaseCollectionEditorsMixin'
+                        100:
+                          label: 'BusPro Finisher'
+                        110:
+                          identifier: 'mapping'
+                          templateName: 'Inspector-TextEditor'
+                          label: 'Mapping'
+                          propertyPath: 'options.mapping'
+                          propertyValidators:
+                            10: 'NotEmpty'
+                    1100:
+                      identifier: 'AddReferrerFinisher'
+                      editors:
+                        __inheritances:
+                          10: 'TYPO3.CMS.Form.mixins.formElementMixins.BaseCollectionEditorsMixin'
+                        100:
+                          label: 'Referrer Finisher'
+
+          finishersDefinition:
+            BpnApiFinisher:
+              formEditor:
+                iconIdentifier: 'form-finisher'
+                predefinedDefaults:
+                  options:
+                    mapping: 'lastName:text-1,firstName:text-2,gender:singleselect-1,email:email-1,street:text-3,zipCode:text-4,city:text-5,phone:telephone-1'
+            AddReferrerFinisher:
+              formEditor:
+                iconIdentifier: 'form-finisher'
diff --git a/public/typo3conf/ext/ep_theme/Configuration/Yaml/FormFinishersFrontend.yaml b/public/typo3conf/ext/ep_theme/Configuration/Yaml/FormFinishersFrontend.yaml
new file mode 100644
index 00000000..b9e8cb73
--- /dev/null
+++ b/public/typo3conf/ext/ep_theme/Configuration/Yaml/FormFinishersFrontend.yaml
@@ -0,0 +1,19 @@
+TYPO3:
+  CMS:
+    Form:
+      prototypes:
+        standard:
+          finishersDefinition:
+            BpnApiFinisher:
+              implementationClassName: 'EP\EpTheme\Form\BpnApiFinisher'
+              formEditor:
+                label: 'BusPro Finisher'
+                options:
+                  identifier: 'BpnApiFinisher'
+                  mapping: 'lastName:text-1,firstName:text-2,gender:singleselect-1,email:email-1,street:text-3,zipCode:text-4,city:text-5,phone:telephone-1'
+            AddReferrerFinisher:
+              implementationClassName: 'EP\EpTheme\Form\AddReferrerFinisher'
+              formEditor:
+                label: 'Referrer Finisher'
+                options:
+                  identifier: 'AddReferrerFinisher'
diff --git a/public/typo3conf/ext/ep_theme/Configuration/Forms/FormSetup.yaml b/public/typo3conf/ext/ep_theme/Configuration/Yaml/FormsBase.yaml
similarity index 61%
rename from public/typo3conf/ext/ep_theme/Configuration/Forms/FormSetup.yaml
rename to public/typo3conf/ext/ep_theme/Configuration/Yaml/FormsBase.yaml
index 255e9b4e..7687bbb7 100644
--- a/public/typo3conf/ext/ep_theme/Configuration/Forms/FormSetup.yaml
+++ b/public/typo3conf/ext/ep_theme/Configuration/Yaml/FormsBase.yaml
@@ -4,26 +4,20 @@ TYPO3:
       persistenceManager:
         allowedExtensionPaths:
           10: EXT:ep_theme/Resources/Private/Forms/
-
       prototypes:
         standard:
-          finishersDefinition:
-            BpnApiFinisher:
-              implementationClassName: 'EP\EpTheme\Form\BpnApiFinisher'
           formElementsDefinition:
             Form:
               renderingOptions:
                 templateRootPaths:
-                  100: 'EXT:ep_theme/Resources/Private/Templates/Form/'
+                  1505042810: 'EXT:ep_theme/Resources/Private/Templates/Form/'
                 partialRootPaths:
-                  100: 'EXT:ep_theme/Resources/Private/Partials/Form/'
+                  1505042810: 'EXT:ep_theme/Resources/Private/Partials/Form/'
                 layoutRootPaths:
-                  100: 'EXT:ep_theme/Resources/Private/Layouts/Form/'
-
+                  1505042810: 'EXT:ep_theme/Resources/Private/Layouts/Form/'
         contactform:
           __inheritances:
             10: 'TYPO3.CMS.Form.prototypes.standard'
-
         applicationform:
           __inheritances:
             10: 'TYPO3.CMS.Form.prototypes.standard'