diff --git a/README.md b/README.md
index 991ac44..d441ae5 100644
--- a/README.md
+++ b/README.md
@@ -35,8 +35,14 @@ Update your application configuration to register the package in `config/app.php
 ],
 ~~~
 
-### 3 - Update ZOOP Laravel configuration
-Rename config.example.php to config.php in `zoop/src/resources/config/` and change the following lines:
+### 3 - Publish ZOOP Laravel configuration
+Use the following command to publish the configuration settings from config.example.php in `zoop/src/resources/config/`:
+
+~~~
+php artisan vendor:publish --provider "Zoop\ZoopServiceProvider" --tag="config"
+~~~
+
+This will create the `config/zoopconfig.php` configuration file. Now, change the following lines:
 
 ~~~
 'defaults'  => [
@@ -128,9 +134,11 @@ class HomeController extends Controller{
         'description' => 'Venda de teste, somente!',
         'statement_descriptor' => 'Descrição de testes',
         'on_behalf_of' => 'bb2a51f1c22a4c30b6bf6819be87ac52',
-        'installment_plan[mode]' => 'interest_free',
-        'installment_plan[number_installments]' => '1',
-        'customer' => 'bb2a51f1c22a4c30b6bf6819be87ac52', //buyer ud
+        'installment_plan' => [
+            'mode' => 'interest_free',
+            'number_installments' => '1'
+        ],
+        'customer' => 'bb2a51f1c22a4c30b6bf6819be87ac52', //buyer id
     ]);
     
     dd($cnp);
diff --git a/src/Contracts/ZoopBuyers.php b/src/Contracts/ZoopBuyers.php
index f157ec1..cf02d52 100644
--- a/src/Contracts/ZoopBuyers.php
+++ b/src/Contracts/ZoopBuyers.php
@@ -20,6 +20,14 @@ public function __construct(APIResource $APIResource);
     */
     public function create($post);
 
+    /**
+     * Update a created Buyer
+     *
+     * @param $buyerID string
+     * @param $post array
+     */
+    public function update($buyerID, $post);
+
     /**
      * Delete a Buyer by id
      *
@@ -34,6 +42,13 @@ public function delete($buyerID);
      */
     public function get($buyerID);
 
+    /**
+     * Retrieve the details of a Buyer by taxpayer_id
+     *
+     * @param $taxpayerID string
+     */
+    public function getByTaxpayerId($taxpayerID);
+
     /**
      * Returns a JSON object with a list of buyers accounts.
      */
diff --git a/src/Contracts/ZoopSubscriptions.php b/src/Contracts/ZoopSubscriptions.php
index e3cfbbc..5cd4559 100644
--- a/src/Contracts/ZoopSubscriptions.php
+++ b/src/Contracts/ZoopSubscriptions.php
@@ -20,7 +20,7 @@ public function __construct(APIResource $APIResource);
     */
     public function create($post);
 
-        /**
+    /**
      * Update a created Subscription
      *
      * @param $subscriptionID string
diff --git a/src/Exceptions/ZoopException.php b/src/Exceptions/ZoopException.php
index 71ea19c..a0180ed 100644
--- a/src/Exceptions/ZoopException.php
+++ b/src/Exceptions/ZoopException.php
@@ -1,5 +1,5 @@
 <?php
 
-namespace Zoop\src\Exceptions;
+namespace Zoop\Exceptions;
 
 class ZoopException extends \Exception {}
\ No newline at end of file
diff --git a/src/Lib/APIRequest.php b/src/Lib/APIRequest.php
index 5b4d564..c7798ae 100644
--- a/src/Lib/APIRequest.php
+++ b/src/Lib/APIRequest.php
@@ -115,14 +115,14 @@ private function requestWithCURL($method, $url, $headers, $data = Array()){
 
         if (strtolower($method) == "post") {
             $opts[CURLOPT_POST] = 1;
-            $opts[CURLOPT_POSTFIELDS] = http_build_query($data);
+            $opts[CURLOPT_POSTFIELDS] = json_encode($data);
         }
 
         if (strtolower($method) == "delete") $opts[CURLOPT_CUSTOMREQUEST] = 'DELETE';
 
         if (strtolower($method) == "put") {
             $opts[CURLOPT_CUSTOMREQUEST] = 'PUT';
-            $opts[CURLOPT_POSTFIELDS] = http_build_query($data);
+            $opts[CURLOPT_POSTFIELDS] = json_encode($data);
         }
 
         $opts[CURLOPT_URL] = $url;
diff --git a/src/Lib/APIResource.php b/src/Lib/APIResource.php
index 99c7662..f98fcba 100644
--- a/src/Lib/APIResource.php
+++ b/src/Lib/APIResource.php
@@ -90,7 +90,7 @@ public function fileAPI($api, $files){
 
                 if(!is_file($files)) throw new ZoopException('Looks like this is not a file...');
 
-                if(!in_array(mime_content_type($files), $mimeTypes)) throw new ZoopException('You can only send files of types "jpg, png, pdf"!');
+                if(!in_array($files->getClientMimeType(), $mimeTypes)) throw new ZoopException('You can only send files of types "jpg, png, pdf"!');
 
                 return $this->APIRequest->request('FILE', $url, $this->zoopBase->getHeaders(), [
                     'file' => new \CURLFile($files ,'' , uniqid()),
diff --git a/src/Lib/ZoopBuyers.php b/src/Lib/ZoopBuyers.php
index 149b309..8defac8 100644
--- a/src/Lib/ZoopBuyers.php
+++ b/src/Lib/ZoopBuyers.php
@@ -29,6 +29,16 @@ public function create($post = []){
         return $this->APIResource->createAPI($api, $post);
     }
 
+    /**
+     * @param string $buyerID
+     * @param array $post
+     * @return mixed
+     */
+    public function update($buyerID, $post){
+        $api = 'buyers/' . $buyerID;
+        return $this->APIResource->updateAPI($api, $post);
+    }
+
     /**
      * @param string $buyerID
      * @return mixed
@@ -47,6 +57,15 @@ public function get($buyerID){
         return $this->APIResource->searchAPI($api);
     }
 
+    /**
+     * @param string $taxpayerID
+     * @return mixed
+     */
+    public function getByTaxpayerId($taxpayerID){
+        $api = 'buyers/search?taxpayer_id='.$taxpayerID;
+        return $this->APIResource->searchAPI($api);
+    }
+
     /**
      * @return mixed
      */