diff --git a/components/header.js b/components/header.js
index ee9c4a6a..c5d7f902 100644
--- a/components/header.js
+++ b/components/header.js
@@ -94,29 +94,39 @@ const Header = (props) => {
             });
     };
 
-    const switchLocale = locale === "en" ? "cy" : "en";
+    //const switchLocale = locale === "en" ? "cy" : "en";
+
+    const switchLocale = router.asPath.startsWith("/cy") ? "en" : "cy";
+
+    console.log("switch locale", locale === "en" ? "cy" : "en");
 
     const handleLocaleSwitch = () => {
-        // Set cookie
-        setCookie(null, "pedw_locale", switchLocale, {
+        // const router = useRouter();
+        const isWelsh = router.asPath.startsWith("/cy");
+
+        console.log(
+            isWelsh,
+            router.asPath,
+            router.basePath,
+            router.pathname,
+            router.route
+        );
+
+        // Switch path: remove /cy if switching to English, add /cy if switching to Welsh
+        const newPath = isWelsh
+            ? router.asPath.replace(/^\/cy/, "") || "/"
+            : router.asPath === "/"
+            ? "/cy"
+            : `/cy${router.asPath}`;
+
+        // Persist user's choice in cookie
+        setCookie(null, "pedw_locale", isWelsh ? "en" : "cy", {
             path: "/",
-            maxAge: 60 * 60 * 24 * 365,
+            maxAge: 60 * 60 * 24 * 365, // 1 year
         });
 
-        // Rebuild URL with query parameters
-        const queryString =
-            Object.keys(router.query).length > 0
-                ? "?" +
-                  Object.entries(router.query)
-                      .map(([key, value]) => `${key}=${value}`)
-                      .join("&")
-                : "";
-
-        // router.push(router.pathname + queryString, undefined, {
-        //     locale: switchLocale,
-        // });
-
-        router.push(router.asPath, router.asPath, { locale: switchLocale });
+        // Navigate to new language path
+        router.push(newPath);
     };
 
     return (
@@ -170,7 +180,7 @@ const Header = (props) => {
                             </Link>
                         )}
 
-                        <span
+                        {/* <span
                             onClick={handleLocaleSwitch}
                             className="govuk-header__link"
                             lang={switchLocale}
@@ -192,8 +202,8 @@ const Header = (props) => {
                             }
                         >
                             {t("common:available-in")}
-                        </span>
-                        {/* <Link
+                        </span> */}
+                        <Link
                             href={
                                 Object.keys(router.query).length > 0
                                     ? router.pathname +
@@ -233,7 +243,7 @@ const Header = (props) => {
                         >
                             {" "}
                             {t("common:available-in")}
-                        </Link> */}
+                        </Link>
                     </div>
                 </div>
             </div>