diff --git a/README.md b/README.md
index 305bf2a..ffefffb 100644
--- a/README.md
+++ b/README.md
@@ -22,10 +22,14 @@ Use it with laravel validator rules in the way you most like: Custom Request, `\
 ```php
 $rules = [
     'cpf' => 'required,cpf',
+    'cnpj' => 'required,cnpj',
+    'cellphone' => 'mobile_br',
 ];
 
 $errorMsgs = [
     'cpf' => 'The :attribute must be a valid Brazilian CPF.',
+    'cnpj' => 'The :attribute must be a valid Brazilian CNPJ.',
+    'cellphone' => 'Invalid mobile number.', // The show is yours, do as you want!
 ];
 
 $validator = \Validator::make($request->all(), $rules, $errorMsgs);
@@ -37,13 +41,17 @@ if($validator->fails()){
 ## To-do List
 
 * [x] Brazilian CPF
-* [ ] Brazilian CNPJ
+* [x] Brazilian CNPJ
 * [x] Brazilian mobile phone with 9 digit
 * [ ] Brazilian Zip code (CEP)
 * [ ] Brazilian landline phone
+* [ ] Exists compound (Multi column exists check)
 
 ## Release History
 
+* 0.3.0
+  * Brazilian CNPJ
+  * ADD: Brazilian CNPJ rule (`cnpj`)
 * 0.2.0
   * Brazilian Mobile (with 9 digit check)
   * ADD: Brazilian Mobile rule (`mobile_br`)
diff --git a/src/CustomRulesServiceProvider.php b/src/CustomRulesServiceProvider.php
index 88f3a27..0b4da1f 100644
--- a/src/CustomRulesServiceProvider.php
+++ b/src/CustomRulesServiceProvider.php
@@ -5,6 +5,7 @@
 use Illuminate\Support\ServiceProvider;
 
 use Wemersonrv\CustomRules\Rules\Cpf;
+use Wemersonrv\CustomRules\Rules\Cnpj;
 use Wemersonrv\CustomRules\Rules\MobileBr;
 
 class CustomRulesServiceProvider extends ServiceProvider
@@ -28,6 +29,9 @@ public function boot()
     {
         \Validator::extend('cpf', function($attribute, $value, $parameter, $validator){
 		    return (new Cpf())->passes($attribute, $value);
+        });
+        \Validator::extend('cnpj', function($attribute, $value, $parameter, $validator){
+		    return (new Cnpj())->passes($attribute, $value);
 	    });
         \Validator::extend('mobile_br', function($attribute, $value, $parameter, $validator){
 		    return (new MobileBr())->passes($attribute, $value);
diff --git a/src/Rules/Cnpj.php b/src/Rules/Cnpj.php
new file mode 100644
index 0000000..0d6af75
--- /dev/null
+++ b/src/Rules/Cnpj.php
@@ -0,0 +1,51 @@
+<?php
+
+namespace Wemersonrv\CustomRules\Rules;
+
+use Illuminate\Contracts\Validation\Rule;
+
+class Cnpj implements Rule
+{
+   /**
+     * Determine if the validation rule passes.
+     *
+     * @param  string  $attribute
+     * @param  mixed  $value
+     * @return bool
+     */
+    public function passes($attribute, $value)
+    {
+        if(!$value) return true;  // Vazio, sem required antes
+        $digitsPattern = '/\d{14}/'; // Regex Padrão de 14 dígitos numéricos
+        $repeatPattern = '/(\d)\1{13}/'; // regex Padrões repetidos: 00000000000000 11111111111111 etc
+
+        if( !preg_match($digitsPattern, $value) // Padrão diferente de 14 digitos numéricos
+            || preg_match($repeatPattern, $value)  // Capturou sequencia
+            || strlen($value) > 14 ){ // mais de 14 digitos
+            return false;
+        }
+        $body = substr($value, 0, 12);
+        $range = '543298765432';
+
+        // Dígitos verificadores
+        for($pass=0; $pass<2; $pass++){
+            $result = 0;
+            for($i=0; $i<strlen($body); $i++){
+                $result += $body[$i] * $range[$i];
+            }
+            $body .= $result % 11 ? 11 - ($result % 11) : 0;
+            $range = "6{$range}";
+        }
+        return $body === $value;
+    }
+
+    /**
+     * Get the validation error message.
+     *
+     * @return string
+     */
+    public function message()
+    {
+        return 'The :attribute must be a valid Brazilian CNPJ.';
+    }
+}