diff --git a/app/Services/SmsBilling/SuperAdminSmsClient.php b/app/Services/SmsBilling/SuperAdminSmsClient.php
index 13a96f1..f2a1a63 100644
--- a/app/Services/SmsBilling/SuperAdminSmsClient.php
+++ b/app/Services/SmsBilling/SuperAdminSmsClient.php
@@ -3,6 +3,7 @@
 namespace App\Services\SmsBilling;
 
 use Illuminate\Http\Client\Response;
+use Illuminate\Support\Facades\Cache;
 use Illuminate\Support\Facades\Http;
 use Illuminate\Support\Facades\Log;
 
@@ -13,14 +14,27 @@ use Illuminate\Support\Facades\Log;
  * Env: SUPERADMIN_SMS_BASE_URL + SUPERADMIN_SMS_SHARED_SECRET
  * Optional: SUPERADMIN_SMS_DOMAIN (else host of APP_URL)
  *
+ * Failover: tries SUPERADMIN_SMS_BASE_URL first (if set), then the three
+ * known SuperAdmin hosts. Last successful base is cached and tried first next time.
+ *
  * Fallback: SUPERADMIN_REMOTE_TOKEN (per-tenant Bearer) if shared secret missing.
  */
 class SuperAdminSmsClient
 {
+    private const SUCCESS_BASE_CACHE_KEY = 'superadmin_sms_success_base';
+
+    private const SUCCESS_BASE_CACHE_TTL_SECONDS = 60 * 60 * 24 * 7;
+
+    /** @var list<string> */
+    private const DEFAULT_BASES = [
+        'https://adm.montzar.ir/api/remote/sms',
+        'https://adm.montech.ir/api/remote/sms',
+        'https://adm.montest.ir/api/remote/sms',
+    ];
+
     public function enabled(): bool
     {
-        $base = trim((string) config('services.superadmin.sms_base_url', ''));
-        if ($base === '') {
+        if ($this->baseUrls() === []) {
             return false;
         }
 
@@ -182,40 +196,158 @@ class SuperAdminSmsClient
             return null;
         }
 
-        try {
-            $pending = Http::withHeaders($this->authHeaders($method, $canonicalPath))
-                ->acceptJson()
-                ->timeout($timeout);
+        $bases = $this->orderedBaseUrls();
+        $method = strtoupper($method);
+        $lastError = null;
 
-            $url = $this->url($relativeUrl);
-            $method = strtoupper($method);
+        foreach ($bases as $index => $base) {
+            try {
+                $pending = Http::withHeaders($this->authHeaders($method, $canonicalPath))
+                    ->acceptJson()
+                    ->timeout($timeout);
 
-            /** @var Response $response */
-            $response = match ($method) {
-                'GET' => $pending->get($url, $query),
-                'POST' => $pending->post($url, $body ?? []),
-                'PUT' => $pending->put($url, $body ?? []),
-                'PATCH' => $pending->patch($url, $body ?? []),
-                default => throw new \InvalidArgumentException("Unsupported method {$method}"),
-            };
+                $url = $this->urlForBase($base, $relativeUrl);
 
-            if (!$response->successful()) {
-                Log::warning("SuperAdmin SMS {$label} failed", [
-                    'status' => $response->status(),
-                    'body' => $response->body(),
+                /** @var Response $response */
+                $response = match ($method) {
+                    'GET' => $pending->get($url, $query),
+                    'POST' => $pending->post($url, $body ?? []),
+                    'PUT' => $pending->put($url, $body ?? []),
+                    'PATCH' => $pending->patch($url, $body ?? []),
+                    default => throw new \InvalidArgumentException("Unsupported method {$method}"),
+                };
+
+                if (!$response->successful()) {
+                    $lastError = 'HTTP '.$response->status();
+                    Log::warning("SuperAdmin SMS {$label} failed", [
+                        'base' => $base,
+                        'candidate' => $index + 1,
+                        'total' => count($bases),
+                        'status' => $response->status(),
+                        'body' => $response->body(),
+                    ]);
+
+                    continue;
+                }
+
+                $data = $response->json();
+                if (!is_array($data)) {
+                    $lastError = 'invalid JSON';
+                    Log::warning("SuperAdmin SMS {$label} invalid JSON", [
+                        'base' => $base,
+                    ]);
+
+                    continue;
+                }
+
+                $this->rememberSuccessfulBase($base);
+
+                return $data;
+            } catch (\Throwable $e) {
+                $lastError = $e->getMessage();
+                Log::warning("SuperAdmin SMS {$label} exception", [
+                    'base' => $base,
+                    'candidate' => $index + 1,
+                    'total' => count($bases),
+                    'error' => $e->getMessage(),
                 ]);
+            }
+        }
 
+        Log::warning("SuperAdmin SMS {$label} unavailable on all bases", [
+            'bases' => $bases,
+            'last_error' => $lastError,
+        ]);
+
+        return null;
+    }
+
+    /**
+     * @return list<string>
+     */
+    private function orderedBaseUrls(): array
+    {
+        $bases = $this->baseUrls();
+        if ($bases === []) {
+            return [];
+        }
+
+        $sticky = $this->readSuccessfulBase();
+        if ($sticky === null || !in_array($sticky, $bases, true)) {
+            return $bases;
+        }
+
+        return array_values(array_unique(array_merge([$sticky], $bases)));
+    }
+
+    /**
+     * Env base (if set) first, then the three known SuperAdmin hosts.
+     * No .env change required when SUPERADMIN_SMS_BASE_URL already points at montzar.
+     *
+     * @return list<string>
+     */
+    private function baseUrls(): array
+    {
+        $out = [];
+
+        $fromEnv = trim((string) config('services.superadmin.sms_base_url', ''));
+        if ($fromEnv !== '') {
+            foreach (preg_split('/[\s,;]+/', $fromEnv) ?: [] as $piece) {
+                $normalized = $this->normalizeBaseUrl((string) $piece);
+                if ($normalized !== '') {
+                    $out[] = $normalized;
+                }
+            }
+        }
+
+        foreach (self::DEFAULT_BASES as $default) {
+            $out[] = $this->normalizeBaseUrl($default);
+        }
+
+        return array_values(array_unique(array_filter($out)));
+    }
+
+    private function normalizeBaseUrl(string $value): string
+    {
+        $base = rtrim(trim($value), '/');
+        if ($base === '') {
+            return '';
+        }
+
+        // Accept origin-only values like https://adm.montzar.ir
+        if (!str_contains($base, '/api/remote/sms')) {
+            $base .= '/api/remote/sms';
+        }
+
+        return rtrim($base, '/');
+    }
+
+    private function urlForBase(string $base, string $path): string
+    {
+        return rtrim($base, '/').'/'.ltrim($path, '/');
+    }
+
+    private function rememberSuccessfulBase(string $base): void
+    {
+        try {
+            Cache::put(self::SUCCESS_BASE_CACHE_KEY, $base, self::SUCCESS_BASE_CACHE_TTL_SECONDS);
+        } catch (\Throwable $e) {
+            Log::debug('SuperAdmin SMS sticky base cache write failed', [
+                'error' => $e->getMessage(),
+            ]);
+        }
+    }
+
+    private function readSuccessfulBase(): ?string
+    {
+        try {
+            $cached = Cache::get(self::SUCCESS_BASE_CACHE_KEY);
+            if (!is_string($cached) || trim($cached) === '') {
                 return null;
             }
 
-            $data = $response->json();
-
-            return is_array($data) ? $data : null;
+            return $this->normalizeBaseUrl($cached);
         } catch (\Throwable $e) {
-            Log::warning("SuperAdmin SMS {$label} exception", [
-                'error' => $e->getMessage(),
-            ]);
-
             return null;
         }
     }
@@ -280,11 +412,4 @@ class SuperAdminSmsClient
 
         return $host;
     }
-
-    private function url(string $path): string
-    {
-        $base = rtrim((string) config('services.superadmin.sms_base_url', ''), '/');
-
-        return $base.'/'.ltrim($path, '/');
-    }
 }
diff --git a/config/services.php b/config/services.php
index 573eb8d..ba9ef15 100644
--- a/config/services.php
+++ b/config/services.php
@@ -42,7 +42,9 @@ return [
     ],
 
     /*
-    | SuperAdmin SMS wallet (source of truth when both env vars are set).
+    | SuperAdmin SMS wallet (source of truth when secret/token is set).
+    | SUPERADMIN_SMS_BASE_URL is optional preferred host; client also fails over to
+    | adm.montzar.ir / adm.montech.ir / adm.montest.ir automatically (no .env change needed).
     | Example: SUPERADMIN_SMS_BASE_URL=https://adm.montzar.ir/api/remote/sms
     */
     'superadmin' => [