diff --git a/src/locales/config.test.ts b/src/locales/config.test.ts
new file mode 100644
index 00000000..f03db03f
--- /dev/null
+++ b/src/locales/config.test.ts
@@ -0,0 +1,38 @@
+import type { RegionCode } from './types';
+
+describe('RegionCode uniqueness', () => {
+  it('should have no duplicate region codes', () => {
+    const codes: RegionCode[] = [
+      'US',
+      'GB',
+      'CA',
+      'AU',
+      'ES',
+      'MX',
+      'AR',
+      'CO',
+      'FR',
+      'BE',
+      'CH',
+      'DE',
+      'AT',
+      'LI',
+      'SA',
+      'AE',
+      'EG',
+      'IL',
+      'JP',
+      'CN',
+      'TW',
+      'HK',
+      'BR',
+      'PT',
+      'RU',
+      'IT',
+      'KR',
+    ];
+
+    const unique = new Set(codes);
+    expect(unique.size).toBe(codes.length);
+  });
+});
diff --git a/src/locales/types.ts b/src/locales/types.ts
index fc27a8ee..0f687067 100644
--- a/src/locales/types.ts
+++ b/src/locales/types.ts
@@ -27,10 +27,10 @@ export type RegionCode =
   | 'CO' // Spanish regions
   | 'FR'
   | 'BE'
-  | 'CH' // French regions
+  | 'CH' // French/German regions (Switzerland)
   | 'DE'
   | 'AT'
-  | 'CH' // German regions
+  | 'LI' // German regions (Liechtenstein)
   | 'SA'
   | 'AE'
   | 'EG' // Arabic regions