diff --git a/src/Payment/Method/Santander.php b/src/Payment/Method/Santander.php
index 0a4e127..17883e7 100644
--- a/src/Payment/Method/Santander.php
+++ b/src/Payment/Method/Santander.php
@@ -24,9 +24,10 @@ public function evaluateCompletion(EvaluationResultFactory $resultFactory): Eval
         }
 
         if (!$this->acceptTos) {
-            return $resultFactory->createErrorMessageEvent()
+            $errorMessageEvent = $resultFactory->createErrorMessageEvent()
                 ->withMessage(__('TOS not accepted'))
                 ->withCustomEvent('payment:method:error');
+            return $resultFactory->createValidation('validateSantanderAcceptTos')->withFailureResult($errorMessageEvent);
 
         }
 
diff --git a/src/view/frontend/layout/hyva_checkout_index_index.xml b/src/view/frontend/layout/hyva_checkout_index_index.xml
new file mode 100644
index 0000000..c13c361
--- /dev/null
+++ b/src/view/frontend/layout/hyva_checkout_index_index.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+      xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
+    <body>
+        <referenceContainer name="hyva.checkout.init-evaluation.after">
+            <block name="hyva.checkout.init-evaluation.validate-santander-accept-tos"
+                   template="Snowdog_HyvaCheckoutSantander::validate-santander-accept-tos.phtml"/>
+        </referenceContainer>
+    </body>
+</page>
diff --git a/src/view/frontend/templates/validate-santander-accept-tos.phtml b/src/view/frontend/templates/validate-santander-accept-tos.phtml
new file mode 100644
index 0000000..f96b555
--- /dev/null
+++ b/src/view/frontend/templates/validate-santander-accept-tos.phtml
@@ -0,0 +1,8 @@
+<script>
+    window.addEventListener('checkout:init:evaluation', event => {
+        hyvaCheckout.evaluation.registerValidator('validateSantanderAcceptTos', (element, component) => {
+            let currentAcceptTos = component.get('acceptTos');
+            return false !== currentAcceptTos;
+        })
+    })
+</script>
