diff --git a/assets/js/src/referral_url_decorator.jsx b/assets/js/src/referral_url_decorator.jsx
new file mode 100644
index 0000000000..76b01a6463
--- /dev/null
+++ b/assets/js/src/referral_url_decorator.jsx
@@ -0,0 +1,16 @@
+const addReferralId = (url) => {
+  if (!window.mailpoet_referral_id) {
+    return url;
+  }
+  const parser = document.createElement('a');
+  parser.href = url;
+  parser.search += parser.search ? '&' : '?';
+  parser.search += `ref=${encodeURIComponent(window.mailpoet_referral_id)}`;
+  return parser.toString();
+
+  // const refUrl = new URL(url);
+  // refUrl.searchParams.set('ref', window.mailpoet_referral_id);
+  // return refUrl.toString();
+};
+
+export default addReferralId;