diff --git a/app/brave_settings_strings.grdp b/app/brave_settings_strings.grdp
index 017b1a1b0a58..8b6cf838a990 100644
--- a/app/brave_settings_strings.grdp
+++ b/app/brave_settings_strings.grdp
@@ -649,6 +649,12 @@
   <message name="IDS_BRAVE_SYNC_CODE_INVALID" desc="Text for general sync setup error.">
     This code is invalid
   </message>
+  <message name="IDS_BRAVE_SYNC_CODE_EMPTY" desc="Text for empty sync setup code provided error.">
+    This code is empty
+  </message>
+  <message name="IDS_BRAVE_SYNC_INTERNAL_SETUP_ERROR" desc="Text for rarely occured sync setup error.">
+    Internal sync setup error
+  </message>
   <message name="IDS_BRAVE_SYNC_CODE_FROM_DEPRECATED_VERSION" desc="Text for error when trying to use old version sync code after v1 sunset date.">
     This code was generated by a deprecated version of Brave, please upgrade your other device first
   </message>
diff --git a/browser/resources/settings/brave_sync_page/brave_sync_setup.ts b/browser/resources/settings/brave_sync_page/brave_sync_setup.ts
index 7fd33bbbf606..ffdce1607eef 100644
--- a/browser/resources/settings/brave_sync_page/brave_sync_setup.ts
+++ b/browser/resources/settings/brave_sync_page/brave_sync_setup.ts
@@ -98,7 +98,7 @@ export class SettingsBraveSyncSetupElement extends SettingsBraveSyncSetupElement
     try {
       success = await this.syncBrowserProxy_.setSyncCode(syncCodeToSubmit)
     } catch (e: unknown) {
-      this.syncCodeValidationError_ = (e as Error).message
+      this.syncCodeValidationError_ = (e as string)
       success = false
     }
     this.isSubmittingSyncCode_ = false
diff --git a/browser/ui/webui/settings/brave_sync_handler.cc b/browser/ui/webui/settings/brave_sync_handler.cc
index 03a818439ad8..909fe15600f3 100644
--- a/browser/ui/webui/settings/brave_sync_handler.cc
+++ b/browser/ui/webui/settings/brave_sync_handler.cc
@@ -208,7 +208,8 @@ void BraveSyncHandler::HandleSetSyncCode(const base::Value::List& args) {
   const std::string time_limited_sync_code = args[1].GetString();
   if (time_limited_sync_code.empty()) {
     LOG(ERROR) << "No sync code parameter provided!";
-    RejectJavascriptCallback(args[0].Clone(), base::Value(false));
+    RejectJavascriptCallback(
+        args[0].Clone(), l10n_util::GetStringUTF8(IDS_BRAVE_SYNC_CODE_EMPTY));
     return;
   }
 
@@ -229,7 +230,10 @@ void BraveSyncHandler::HandleSetSyncCode(const base::Value::List& args) {
   auto* sync_service = GetSyncService();
   if (!sync_service ||
       !sync_service->SetSyncCode(pure_words_with_status.value())) {
-    RejectJavascriptCallback(args[0].Clone(), base::Value(false));
+    LOG(ERROR) << "sync_service=" << sync_service;
+    RejectJavascriptCallback(
+        args[0].Clone(),
+        l10n_util::GetStringUTF8(IDS_BRAVE_SYNC_INTERNAL_SETUP_ERROR));
     return;
   }