diff --git a/phpunit.xml b/phpunit.xml
index 08db8c0..7463ccf 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -14,7 +14,7 @@
     <!-- Indicando qual é o diretório onde as classes de teste se encontram -->
     <testsuites>
         <testsuite name="Orçamentos Coderockr">
-            <directory suffix=".php">src/</directory>
+            <directory suffix=".php">tests/</directory>
         </testsuite>
     </testsuites>
  
diff --git a/src/Orcamentos/Filter/CNPJMask.php b/src/Orcamentos/Filter/CNPJMask.php
new file mode 100644
index 0000000..d4f7573
--- /dev/null
+++ b/src/Orcamentos/Filter/CNPJMask.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace Orcamentos\Filter;
+
+/**
+ * Class CNPJMask
+ * @package Orcamentos\Filter
+ */
+class CNPJMask
+{
+    /**
+     * @param $cnpj
+     * @return string
+     */
+    public function removeMask($cnpj)
+    {
+        return (string)preg_replace("/\D/", '', $cnpj);
+    }
+
+    /**
+     * @param $cnpj
+     * @return string
+     */
+    public function applyMask($cnpj)
+    {
+        // asserting that only digits will be present
+        $cnpj = $this->removeMask($cnpj);
+
+        // applying 14 digits
+        $cnpj = str_pad($cnpj, 14, '0', STR_PAD_LEFT);
+
+        $pattern = "/(\d{2})(\d{3})(\d{3})(\d{4})(\d{2})/";
+        $replacement = "\$1.\$2.\$3/\$4-\$5";
+
+        return (string)preg_replace($pattern, $replacement, $cnpj);
+    }
+}
diff --git a/src/Orcamentos/Model/Client.php b/src/Orcamentos/Model/Client.php
index 2cfa0ec..35bf7c2 100644
--- a/src/Orcamentos/Model/Client.php
+++ b/src/Orcamentos/Model/Client.php
@@ -3,6 +3,7 @@
 
 use Doctrine\ORM\Mapping as ORM;
 use DateTime;
+use Orcamentos\Filter\CNPJMask;
 
 /**
  * @ORM\Entity
@@ -91,11 +92,15 @@ public function setName($name)
     
     public function getCnpj()
     {
-        return $this->cnpj;
+        $cnpjMask = new CNPJMask();
+        return $cnpjMask->applyMask($this->cnpj);
     }
     
     public function setCnpj($cnpj)
     {
+        $cnpjMask = new CNPJMask();
+        $cnpj = $cnpjMask->removeMask($cnpj);
+
         return $this->cnpj = $cnpj;
     }
 
diff --git a/src/Orcamentos/Test/ApplicationTestCase.php b/src/Orcamentos/Test/ApplicationTestCase.php
index c870e3c..c0f4b3a 100644
--- a/src/Orcamentos/Test/ApplicationTestCase.php
+++ b/src/Orcamentos/Test/ApplicationTestCase.php
@@ -3,9 +3,8 @@
 namespace Orcamentos\Test;
 
 use Mockery as m;
-use PHPUnit_Framework_TestCase;
 
-class ApplicationTestCase extends PHPUnit_Framework_TestCase
+class ApplicationTestCase extends \PHPUnit\Framework\TestCase
 {
     protected $repositoryMock;
     protected $emMock;
diff --git a/tests/src/Orcamentos/Filter/CNPJMaskTest.php b/tests/src/Orcamentos/Filter/CNPJMaskTest.php
new file mode 100644
index 0000000..f53d099
--- /dev/null
+++ b/tests/src/Orcamentos/Filter/CNPJMaskTest.php
@@ -0,0 +1,68 @@
+<?php
+
+namespace Orcamentos\Service;
+
+use Orcamentos\Filter\CNPJMask;
+
+/**
+ * Class CNPJMaskTest
+ * @package Orcamentos\Service
+ */
+class CNPJMaskTest extends \PHPUnit\Framework\TestCase
+{
+    public function dataForAddMask()
+    {
+        return array(
+            array(
+                'expected' => '18.915.219/0001-86',
+                'actual' => '18915219000186'
+            ),
+            array(
+                'expected' => '09.376.674/0001-60',
+                'actual' => '09376674000160'
+            ),
+            array(
+                'expected' => '09.376.674/0001-60',
+                'actual' => 9376674000160
+            )
+        );
+    }
+
+    public function dataForRemoveMask()
+    {
+        return array(
+            array(
+                'actual' => '18.915.219/0001-86',
+                'expected' => 18915219000186
+            ),
+            array(
+                'actual' => '09.376.674/0001-60',
+                'expected' => 9376674000160
+            )
+        );
+    }
+
+    /**
+     * @dataProvider dataForRemoveMask
+     */
+    public function testRemoveMask($actual, $expected)
+    {
+        $filter = new CNPJMask();
+
+        $cnpj = $filter->removeMask($actual);
+
+        $this->assertEquals($expected, $cnpj);
+    }
+
+    /**
+     * @dataProvider dataForAddMask
+     */
+    public function testApplyMask($expected, $actual)
+    {
+        $filter = new CNPJMask();
+
+        $cnpj = $filter->applyMask($actual);
+
+        $this->assertEquals($expected, $cnpj);
+    }
+}