diff --git a/admin-dev/tabs/AdminCarriers.php b/admin-dev/tabs/AdminCarriers.php
index 45de6569b..5dcb53289 100644
--- a/admin-dev/tabs/AdminCarriers.php
+++ b/admin-dev/tabs/AdminCarriers.php
@@ -50,9 +50,10 @@ class AdminCarriers extends AdminTab
 
 		$this->optionsList = array(
 			'general' => array(
-				'title' =>	$this->l('Carrier options'),
-				'fields' =>	array(
-					'PS_CARRIER_DEFAULT' => array('title' => $this->l('Default carrier:'), 'desc' => $this->l('The default carrier used in shop'), 'cast' => 'intval', 'type' => 'select', 'identifier' => 'id_carrier', 'list' => Carrier::getCarriers((int)Configuration::get('PS_LANG_DEFAULT'), true , false,false, NULL, Carrier::ALL_CARRIERS)),
+				'title' => $this->l('Carrier options'),
+				'fields' => array(
+					'PS_CARRIER_DEFAULT' => array('title' => $this->l('Default carrier:'), 'desc' => $this->l('The default carrier used in shop'), 'cast' => 'intval', 'type' => 'select',
+					'identifier' => 'id_carrier', 'list' => Carrier::getCarriers((int)Configuration::get('PS_LANG_DEFAULT'), true, false, false, null, Carrier::ALL_CARRIERS)),
 				),
 			),
 		);
@@ -62,8 +63,8 @@ class AdminCarriers extends AdminTab
 
 	public function displayTop()
 	{
-		echo 
-		'<div class="hint clear" style="display:block;">'.
+		echo '
+		<div class="hint clear" style="display:block;">'.
 			'&nbsp;<b>'.$this->l('How to create a new carrier?').'</b>'.
 			'<br />'.
 			'<ul>'.'
@@ -133,11 +134,11 @@ class AdminCarriers extends AdminTab
 					$carrier_zones = $obj->getZones();
 					$carrier_zones_ids = array();
 					if (is_array($carrier_zones))
-						foreach($carrier_zones as $carrier_zone)
+						foreach ($carrier_zones as $carrier_zone)
 							$carrier_zones_ids[] = $carrier_zone['id_zone'];
 					
 					$zones = Zone::getZones(false);
-					foreach ($zones AS $zone)
+					foreach ($zones as $zone)
 						echo '<input type="checkbox" id="zone_'.$zone['id_zone'].'" name="zone_'.$zone['id_zone'].'" value="true" '.
 							Tools::getValue('zone_'.$zone['id_zone'], (in_array($zone['id_zone'], $carrier_zones_ids) ? ' checked="checked"' : '')).'>
 							<label class="t" for="zone_'.$zone['id_zone'].'"> <b>'.$zone['name'].'</b></label><br />';
@@ -147,7 +148,7 @@ class AdminCarriers extends AdminTab
 				<label>'.$this->l('Group access').'</label>
 				<div class="margin-form">';
 					$groups = Group::getGroups(Context::getContext()->language->id);
-					if (sizeof($groups))
+					if (count($groups))
 					{
 						echo '
 					<table cellspacing="0" cellpadding="0" class="table" style="width: 28em;">
@@ -160,7 +161,9 @@ class AdminCarriers extends AdminTab
 						foreach ($groups as $group)
 							echo '
 							<tr class="'.($irow++ % 2 ? 'alt_row' : '').'">
-								<td><input type="checkbox" name="groupBox[]" class="groupBox" id="groupBox_'.$group['id_group'].'" value="'.$group['id_group'].'" '.((Db::getInstance()->getValue('SELECT id_group FROM '._DB_PREFIX_.'carrier_group WHERE id_carrier='.(int)($obj->id).' AND id_group='.(int)($group['id_group'])) OR (!isset($obj->id))) ? 'checked="checked" ' : '').'/></td>
+								<td><input type="checkbox" name="groupBox[]" class="groupBox" id="groupBox_'.$group['id_group'].'" value="'.$group['id_group'].'"
+								'.((Db::getInstance()->getValue('SELECT id_group FROM '._DB_PREFIX_.'carrier_group
+									WHERE id_carrier='.(int)($obj->id).' AND id_group='.(int)($group['id_group'])) || (!isset($obj->id))) ? 'checked="checked" ' : '').'/></td>
 								<td>'.$group['id_group'].'</td>
 								<td><label for="groupBox_'.$group['id_group'].'" class="t">'.$group['name'].'</label></td>
 							</tr>';
@@ -191,9 +194,9 @@ class AdminCarriers extends AdminTab
 				<div id="shipping_costs_div">
 				<label>'.$this->l('Tax').'</label>
 				<div class="margin-form">
-					 <select name="id_tax_rules_group" id="id_tax_rules_group" '.(Tax::excludeTaxeOption() ? 'disabled="disabled"' : '' ).'>
-					    <option value="0">'.$this->l('No Tax').'</option>';
-						foreach (TaxRulesGroup::getTaxRulesGroups(true) AS $tax_rules_group)
+					<select name="id_tax_rules_group" id="id_tax_rules_group" '.(Tax::excludeTaxeOption() ? 'disabled="disabled"' : '' ).'>
+						<option value="0">'.$this->l('No Tax').'</option>';
+						foreach (TaxRulesGroup::getTaxRulesGroups(true) as $tax_rules_group)
 							echo '<option value="'.$tax_rules_group['id_tax_rules_group'].'" '.(($this->getFieldValue($obj, 'id_tax_rules_group') == $tax_rules_group['id_tax_rules_group']) ? ' selected="selected"' : '').'>'.$tax_rules_group['name'].'</option>';
 				echo '</select>
 				</div>
@@ -222,7 +225,7 @@ class AdminCarriers extends AdminTab
 					</select>
 					<p>'.$this->l('Out-of-range behavior when none is defined (e.g., when a customer\'s cart weight is greater than the highest range limit)').'</p>
 				</div>';
-				if($this->getFieldValue($obj, 'is_module'))
+				if ($this->getFieldValue($obj, 'is_module'))
 				{
 					echo '<label>'.$this->l('Module:').' </label>
 						  <div class="margin-form"><p> - '.
@@ -230,12 +233,12 @@ class AdminCarriers extends AdminTab
 						  <input type="hidden" name="is_module" value="1">
 						  <input type="hidden" name="external_module_name" value="'.$this->getFieldValue($obj, 'external_module_name').'">';
 
-					if($this->getFieldValue($obj, 'shipping_external'))
+					if ($this->getFieldValue($obj, 'shipping_external'))
 					{
 						echo '<p> - '.$this->l('The shipping costs are calculated outside of your shop').'</p>
 						<input type="hidden" name="shipping_external" value="1">';
 					}
-					if($this->getFieldValue($obj, 'need_range'))
+					if ($this->getFieldValue($obj, 'need_range'))
 					{
 						echo '<p> - '.$this->l('This carrier uses PrestaShop range to calculate shipping costs').'</p>
 						<input type="hidden" name="need_range" value="1">';
@@ -275,7 +278,7 @@ class AdminCarriers extends AdminTab
 			Db::getInstance()->Execute('DELETE FROM '._DB_PREFIX_.'carrier_group WHERE id_carrier='.(int)($id_carrier));
 		$groups = Db::getInstance()->ExecuteS('SELECT id_group FROM `'._DB_PREFIX_.'group`');
 		foreach ($groups as $group)
-			if (in_array($group['id_group'], $_POST['groupBox']))
+			if (Tools::getIsset('groupBox') && in_array($group['id_group'], Tools::getValue('groupBox')))
 				Db::getInstance()->Execute('INSERT INTO '._DB_PREFIX_.'carrier_group (id_group, id_carrier) VALUES('.(int)($group['id_group']).','.(int)($id_carrier).')');
 	}
 
@@ -285,12 +288,12 @@ class AdminCarriers extends AdminTab
 		{
 		 	/* Checking fields validity */
 			$this->validateRules();
-			if (!sizeof($this->_errors))
+			if (!count($this->_errors))
 			{
 				$id = (int)(Tools::getValue('id_'.$this->table));
 
 				/* Object update */
-				if (isset($id) AND !empty($id))
+				if (isset($id) && !empty($id))
 				{
 					if ($this->tabAccess['edit'] === '1')
 					{
@@ -311,7 +314,7 @@ class AdminCarriers extends AdminTab
 							$this->changeGroups($objectNew->id);
 							if (!$result)
 								$this->_errors[] = Tools::displayError('An error occurred while updating object.').' <b>'.$this->table.'</b>';
-							elseif ($this->postImage($objectNew->id))
+							else if ($this->postImage($objectNew->id))
 								{
 									$this->changeZones($objectNew->id);
 									Tools::redirectAdmin(self::$currentIndex.'&id_'.$this->table.'='.$object->id.'&conf=4'.'&token='.$this->token);
@@ -333,7 +336,7 @@ class AdminCarriers extends AdminTab
 						$this->copyFromPost($object, $this->table);
 						if (!$object->add())
 							$this->_errors[] = Tools::displayError('An error occurred while creating object.').' <b>'.$this->table.'</b>';
-						elseif (($_POST['id_'.$this->table] = $object->id /* voluntary */) AND $this->postImage($object->id) AND $this->_redirect)
+						else if (($_POST['id_'.$this->table] = $object->id /* voluntary */) && $this->postImage($object->id) && $this->_redirect)
 						{
 							$this->changeZones($object->id);
 							$this->changeGroups($object->id);
@@ -348,7 +351,7 @@ class AdminCarriers extends AdminTab
 		else
 		{
 			if ((Tools::isSubmit('submitDel'.$this->table) && in_array(Configuration::get('PS_CARRIER_DEFAULT'), Tools::getValue('carrierBox')))
-				OR (isset($_GET['delete'.$this->table]) AND Tools::getValue('id_carrier') == Configuration::get('PS_CARRIER_DEFAULT')))
+				|| (isset($_GET['delete'.$this->table]) && Tools::getValue('id_carrier') == Configuration::get('PS_CARRIER_DEFAULT')))
 					$this->_errors[] = $this->l('Please set another carrier as default before deleting');
 			else
 				parent::postProcess();
@@ -356,24 +359,24 @@ class AdminCarriers extends AdminTab
 	}
 
 
-	function changeZones($id)
+	public function changeZones($id)
 	{
 		$carrier = new $this->className($id);
 		if (!Validate::isLoadedObject($carrier))
 			die (Tools::displayError('Object cannot be loaded'));
 		$zones = Zone::getZones(true);
 		foreach ($zones as $zone)
-			if (sizeof($carrier->getZone($zone['id_zone'])))
+			if (count($carrier->getZone($zone['id_zone'])))
 			{
-				if (!isset($_POST['zone_'.$zone['id_zone']]) OR !$_POST['zone_'.$zone['id_zone']])
+				if (!isset($_POST['zone_'.$zone['id_zone']]) || !$_POST['zone_'.$zone['id_zone']])
 					$carrier->deleteZone($zone['id_zone']);
 			}
 			else
-				if (isset($_POST['zone_'.$zone['id_zone']]) AND $_POST['zone_'.$zone['id_zone']])
+				if (isset($_POST['zone_'.$zone['id_zone']]) && $_POST['zone_'.$zone['id_zone']])
 					$carrier->addZone($zone['id_zone']);
 	}
 
-	public function displayListContent($token = NULL)
+	public function displayListContent($token = null)
 	{
 		foreach ($this->_list as $key => $list)
 			if ($list['name'] == '0')
diff --git a/classes/Carrier.php b/classes/Carrier.php
index ad456a253..aa4fa643a 100644
--- a/classes/Carrier.php
+++ b/classes/Carrier.php
@@ -42,58 +42,59 @@ class CarrierCore extends ObjectModel
 	const SHIPPING_METHOD_FREE = 3;
 
 	/** @var int Tax id (none = 0) */
-	public		$id_tax_rules_group;
+	public $id_tax_rules_group;
 
  	/** @var string Name */
-	public 		$name;
+	public $name;
 
  	/** @var string URL with a '@' for */
-	public 		$url;
+	public $url;
 
 	/** @var string Delay needed to deliver customer */
-	public 		$delay;
+	public $delay;
 
 	/** @var boolean Carrier statuts */
-	public 		$active = true;
+	public $active = true;
 
 	/** @var boolean True if carrier has been deleted (staying in database as deleted) */
-	public 		$deleted = 0;
+	public $deleted = 0;
 
 	/** @var boolean Active or not the shipping handling */
-	public		$shipping_handling = true;
+	public $shipping_handling = true;
 
 	/** @var int Behavior taken for unknown range */
-	public		$range_behavior;
+	public $range_behavior;
 
 	/** @var boolean Carrier module */
-	public		$is_module;
+	public $is_module;
 
 	/** @var boolean Free carrier */
-	public		$is_free = false;
+	public $is_free = false;
 
 	/** @var int shipping behavior: by weight or by price */
-	public 		$shipping_method = 0;
+	public $shipping_method = 0;
 
 	/** @var boolean Shipping external */
-	public		$shipping_external = 0;
+	public $shipping_external = 0;
 
 	/** @var string Shipping external */
-	public		$external_module_name = NULL;
+	public $external_module_name = null;
 
 	/** @var boolean Need Range */
-	public		$need_range = 0;
+	public $need_range = 0;
 
-	protected	$langMultiShop = true;
+	protected $langMultiShop = true;
 
- 	protected 	$fieldsRequired = array('name', 'active');
- 	protected 	$fieldsSize = array('name' => 64);
- 	protected 	$fieldsValidate = array('id_tax_rules_group' => 'isInt', 'name' => 'isCarrierName', 'active' => 'isBool', 'is_free' => 'isBool', 'url' => 'isAbsoluteUrl', 'shipping_handling' => 'isBool', 'range_behavior' => 'isBool', 'shipping_method' => 'isUnsignedInt');
- 	protected 	$fieldsRequiredLang = array('delay');
- 	protected 	$fieldsSizeLang = array('delay' => 128);
- 	protected 	$fieldsValidateLang = array('delay' => 'isGenericName');
+	protected $fieldsRequired = array('name', 'active');
+	protected $fieldsSize = array('name' => 64);
+	protected $fieldsValidate = array('id_tax_rules_group' => 'isInt', 'name' => 'isCarrierName', 'active' => 'isBool',
+		'is_free' => 'isBool', 'url' => 'isAbsoluteUrl', 'shipping_handling' => 'isBool', 'range_behavior' => 'isBool', 'shipping_method' => 'isUnsignedInt');
+	protected $fieldsRequiredLang = array('delay');
+	protected $fieldsSizeLang = array('delay' => 128);
+	protected $fieldsValidateLang = array('delay' => 'isGenericName');
 
-	protected 	$table = 'carrier';
-	protected 	$identifier = 'id_carrier';
+	protected $table = 'carrier';
+	protected $identifier = 'id_carrier';
 
 	protected static $priceByWeight = array();
 	protected static $priceByWeight2 = array();
@@ -130,7 +131,7 @@ class CarrierCore extends ObjectModel
 		return $fields;
 	}
 
-	public function __construct($id = NULL, $id_lang = NULL)
+	public function __construct($id = null, $id_lang = null)
 	{
 		parent::__construct($id, $id_lang);
 		if ($this->name == '0')
@@ -150,7 +151,7 @@ class CarrierCore extends ObjectModel
 
 	public function add($autodate = true, $nullValues = false)
 	{
-		if (!parent::add($autodate, $nullValues) OR !Validate::isLoadedObject($this))
+		if (!parent::add($autodate, $nullValues) || !Validate::isLoadedObject($this))
 			return false;
 		if (!Db::getInstance()->ExecuteS('SELECT `id_carrier` FROM `'._DB_PREFIX_.$this->table.'` WHERE `deleted` = 0'))
 			return false;
@@ -158,6 +159,10 @@ class CarrierCore extends ObjectModel
 			return false;
 		if ((int)($numRows) == 1)
 			Configuration::updateValue('PS_CARRIER_DEFAULT', (int)($this->id));
+		
+		// Register reference
+		Db::getInstance()->Execute('UPDATE `'._DB_PREFIX_.$this->table.'` SET `id_reference` = '.$this->id.' WHERE `id_carrier` = '.$this->id);
+		
 		return true;
 	}
 
@@ -201,7 +206,7 @@ class CarrierCore extends ObjectModel
 		return self::$priceByWeight[$cache_key];
 	}
 
-	static public function checkDeliveryPriceByWeight($id_carrier, $totalWeight, $id_zone, Shop $shop = null)
+	public static function checkDeliveryPriceByWeight($id_carrier, $totalWeight, $id_zone, Shop $shop = null)
 	{
 		$cache_key = $id_carrier.'_'.$totalWeight.'_'.$id_zone;
 		if (!isset(self::$priceByWeight2[$cache_key]))
@@ -243,7 +248,7 @@ class CarrierCore extends ObjectModel
 	 * @param integer $id_zone Zone id (for customer delivery address)
 	 * @return float Delivery price
 	 */
-	public function getDeliveryPriceByPrice($orderTotal, $id_zone, $id_currency = NULL, Shop $shop = null)
+	public function getDeliveryPriceByPrice($orderTotal, $id_zone, $id_currency = null, Shop $shop = null)
 	{
 		$cache_key = $this->id.'_'.$orderTotal.'_'.$id_zone.'_'.$id_currency;
 		if (!isset(self::$priceByPrice[$cache_key]))
@@ -278,7 +283,7 @@ class CarrierCore extends ObjectModel
 	 * @param integer $id_currency
 	 * @return float Delivery price
 	 */
-	static public function checkDeliveryPriceByPrice($id_carrier, $orderTotal, $id_zone, $id_currency = NULL, Shop $shop = null)
+	public static function checkDeliveryPriceByPrice($id_carrier, $orderTotal, $id_zone, $id_currency = null, Shop $shop = null)
 	{
 		$cache_key = $id_carrier.'_'.$orderTotal.'_'.$id_zone.'_'.$id_currency;
 		if (!isset(self::$priceByPrice2[$cache_key]))
@@ -349,11 +354,11 @@ class CarrierCore extends ObjectModel
 	 * @param boolean $active Returns only active carriers when true
 	 * @return array Carriers
 	 */
-	public static function getCarriers($id_lang, $active = false, $delete = false, $id_zone = false, $ids_group = NULL, $modules_filters = self::PS_CARRIERS_ONLY)
+	public static function getCarriers($id_lang, $active = false, $delete = false, $id_zone = false, $ids_group = null, $modules_filters = self::PS_CARRIERS_ONLY)
 	{
-	 	if (!Validate::isBool($active))
-	 		die(Tools::displayError());
-	 	if ($ids_group)
+		if (!Validate::isBool($active))
+			die(Tools::displayError());
+		if ($ids_group)
 		{
 			$ids = '';
 			foreach ($ids_group as $id)
@@ -366,8 +371,8 @@ class CarrierCore extends ObjectModel
 		$sql = 'SELECT c.*, cl.delay
 				FROM `'._DB_PREFIX_.'carrier` c
 				LEFT JOIN `'._DB_PREFIX_.'carrier_lang` cl ON (c.`id_carrier` = cl.`id_carrier` AND cl.`id_lang` = '.(int)$id_lang.Context::getContext()->shop->sqlLang('cl').')
-				LEFT JOIN `'._DB_PREFIX_.'carrier_zone` cz  ON (cz.`id_carrier` = c.`id_carrier`)'.
-				($id_zone ? 'LEFT JOIN `'._DB_PREFIX_.'zone` z  ON (z.`id_zone` = '.(int)$id_zone.')' : '').'
+				LEFT JOIN `'._DB_PREFIX_.'carrier_zone` cz ON (cz.`id_carrier` = c.`id_carrier`)'.
+				($id_zone ? 'LEFT JOIN `'._DB_PREFIX_.'zone` z ON (z.`id_zone` = '.(int)$id_zone.')' : '').'
 				WHERE c.`deleted` = '.($delete ? '1' : '0').
 					($active ? ' AND c.`active` = 1' : '').
 					($id_zone ? ' AND cz.`id_zone` = '.(int)$id_zone.'
@@ -396,7 +401,7 @@ class CarrierCore extends ObjectModel
 
 		$carriers = Db::getInstance()->ExecuteS($sql);
 
-		if (is_array($carriers) AND count($carriers))
+		if (is_array($carriers) && count($carriers))
 		{
 			foreach ($carriers as $key => $carrier)
 				if ($carrier['name'] == '0')
@@ -408,10 +413,10 @@ class CarrierCore extends ObjectModel
 		return $carriers;
 	}
 
-	public static function getDeliveredCountries($id_lang, $activeCountries = false, $activeCarriers = false, $containStates = NULL)
+	public static function getDeliveredCountries($id_lang, $activeCountries = false, $activeCarriers = false, $containStates = null)
 	{
-		if (!Validate::isBool($activeCountries) OR !Validate::isBool($activeCarriers))
-	 		die(Tools::displayError());
+		if (!Validate::isBool($activeCountries) || !Validate::isBool($activeCarriers))
+			die(Tools::displayError());
 
 		$states = Db::getInstance(_PS_USE_SQL_SLAVE_)->ExecuteS('
 		SELECT s.*
@@ -430,9 +435,9 @@ class CarrierCore extends ObjectModel
 			ORDER BY cl.name ASC');
 
 		$countries = array();
-		foreach ($result AS &$country)
+		foreach ($result as &$country)
 			$countries[$country['id_country']] = $country;
-		foreach ($states AS &$state)
+		foreach ($states as &$state)
 			if (isset($countries[$state['id_country']])) /* Does not keep the state if its country has been disabled and not selected */
 				$countries[$state['id_country']]['states'][] = $state;
 
@@ -445,46 +450,47 @@ class CarrierCore extends ObjectModel
 	 * @param Array $groups group of the customer
 	 * @return Array
 	 */
-	public static function getCarriersForOrder($id_zone, $groups = NULL)
+	public static function getCarriersForOrder($id_zone, $groups = null)
 	{
 		$context = Context::getContext();
 		$id_lang = $context->language->id;
 		$cart = $context->cart;
 		$id_currency = $context->currency->id;
 
-		if (is_array($groups) AND !empty($groups))
+		if (is_array($groups) && !empty($groups))
 			$result = Carrier::getCarriers($id_lang, true, false, (int)$id_zone, $groups, self::PS_CARRIERS_AND_CARRIER_MODULES_NEED_RANGE);
 		else
 			$result = Carrier::getCarriers($id_lang, true, false, (int)$id_zone, array(1), self::PS_CARRIERS_AND_CARRIER_MODULES_NEED_RANGE);
 		$resultsArray = array();
 
-		foreach ($result AS $k => $row)
+		foreach ($result as $k => $row)
 		{
 			$carrier = new Carrier((int)$row['id_carrier']);
 			$shippingMethod = $carrier->getShippingMethod();
 			if ($shippingMethod != Carrier::SHIPPING_METHOD_FREE)
 			{
 			// Get only carriers that are compliant with shipping method
-				if (($shippingMethod == Carrier::SHIPPING_METHOD_WEIGHT AND $carrier->getMaxDeliveryPriceByWeight($id_zone) === false)
-					OR ($shippingMethod == Carrier::SHIPPING_METHOD_PRICE AND $carrier->getMaxDeliveryPriceByPrice($id_zone) === false))
+				if (($shippingMethod == Carrier::SHIPPING_METHOD_WEIGHT && $carrier->getMaxDeliveryPriceByWeight($id_zone) === false)
+					|| ($shippingMethod == Carrier::SHIPPING_METHOD_PRICE && $carrier->getMaxDeliveryPriceByPrice($id_zone) === false))
 			{
 				unset($result[$k]);
-				continue ;
+				continue;
 			}
 
 			// If out-of-range behavior carrier is set on "Desactivate carrier"
 			if ($row['range_behavior'])
 			{
 				// Get id zone
-		        if (!$id_zone)
+				if (!$id_zone)
 						$id_zone = Country::getIdZone(Country::getDefaultCountryId());
 
 				// Get only carriers that have a range compatible with cart
-					if (($shippingMethod == Carrier::SHIPPING_METHOD_WEIGHT AND (!Carrier::checkDeliveryPriceByWeight($row['id_carrier'], $cart->getTotalWeight(), $id_zone)))
-						OR ($shippingMethod == Carrier::SHIPPING_METHOD_PRICE AND (!Carrier::checkDeliveryPriceByPrice($row['id_carrier'], $cart->getOrderTotal(true, Cart::BOTH_WITHOUT_SHIPPING), $id_zone, $id_currency))))
+					if (($shippingMethod == Carrier::SHIPPING_METHOD_WEIGHT && (!Carrier::checkDeliveryPriceByWeight($row['id_carrier'], $cart->getTotalWeight(), $id_zone)))
+						|| ($shippingMethod == Carrier::SHIPPING_METHOD_PRICE
+						&& (!Carrier::checkDeliveryPriceByPrice($row['id_carrier'], $cart->getOrderTotal(true, Cart::BOTH_WITHOUT_SHIPPING), $id_zone, $id_currency))))
 					{
 						unset($result[$k]);
-						continue ;
+						continue;
 					}
 			}
 			}
@@ -498,7 +504,7 @@ class CarrierCore extends ObjectModel
 			if ($row['price'] === false)
 			{
 				unset($result[$k]);
-				continue ;
+				continue;
 			}
 
 			$resultsArray[] = $row;
@@ -511,8 +517,8 @@ class CarrierCore extends ObjectModel
 		return Db::getInstance(_PS_USE_SQL_SLAVE_)->ExecuteS('
 			SELECT c.`id_carrier`
 			FROM `'._DB_PREFIX_.'carrier` c
-			LEFT JOIN `'._DB_PREFIX_.'carrier_zone` cz  ON (cz.`id_carrier` = c.`id_carrier`)
-			LEFT JOIN `'._DB_PREFIX_.'zone` z  ON (z.`id_zone` = '.(int)($id_zone).')
+			LEFT JOIN `'._DB_PREFIX_.'carrier_zone` cz ON (cz.`id_carrier` = c.`id_carrier`)
+			LEFT JOIN `'._DB_PREFIX_.'zone` z ON (z.`id_zone` = '.(int)($id_zone).')
 			WHERE c.`id_carrier` = '.(int)($id_carrier).'
 			AND c.`deleted` = 0
 			AND c.`active` = 1
@@ -532,7 +538,7 @@ class CarrierCore extends ObjectModel
 			SELECT *
 			FROM `'._DB_PREFIX_.'carrier_zone` cz
 			LEFT JOIN `'._DB_PREFIX_.'zone` z ON cz.`id_zone` = z.`id_zone`
-			WHERE cz.`id_carrier` = '. (int)($this->id));
+			WHERE cz.`id_carrier` = '.(int)($this->id));
 	}
 
 	/**
@@ -632,7 +638,7 @@ class CarrierCore extends ObjectModel
 				else if (is_int($v) || is_float($v))
 					$sql .= $v;
 				else
-					$sql .= "'$v'";
+					$sql .= '\''.$v.'\'';
 				$sql .= ', ';
 			}
 			$sql = rtrim($sql, ', ').'), ';
@@ -664,7 +670,7 @@ class CarrierCore extends ObjectModel
 			$sql = 'SELECT id_'.$range.' id_range, delimiter1, delimiter2 FROM `'._DB_PREFIX_.$range.'`
 					WHERE id_carrier = '.(int)$oldId;
 			$res = Db::getInstance()->ExecuteS($sql);
-			foreach ($res AS $val)
+			foreach ($res as $val)
 			{
 				$sql = 'INSERT INTO `'._DB_PREFIX_.$range.'` (`id_carrier`, `delimiter1`, `delimiter2`)
 						VALUES ('.$this->id.','.(float)$val['delimiter1'].','.(float)$val['delimiter2'].')';
@@ -682,9 +688,8 @@ class CarrierCore extends ObjectModel
 		}
 
 		// Copy existing zones
-		$sql = 'SELECT * FROM `'._DB_PREFIX_.'carrier_zone`
-				WHERE id_carrier = '.(int)$oldId;
-		$res = Db::getInstance()->ExecuteS($sql);
+		$res = Db::getInstance()->ExecuteS('SELECT * FROM `'._DB_PREFIX_.'carrier_zone`
+			WHERE id_carrier = '.(int)$oldId);
 		foreach ($res as $val)
 			Db::getInstance()->Execute('
 			INSERT INTO `'._DB_PREFIX_.'carrier_zone` (`id_carrier`, `id_zone`)
@@ -693,8 +698,27 @@ class CarrierCore extends ObjectModel
 		//Copy default carrier
 		if ((int)(Configuration::get('PS_CARRIER_DEFAULT')) == $oldId)
 			Configuration::updateValue('PS_CARRIER_DEFAULT', (int)($this->id));
+		
+		// Copy reference
+		$id_reference = Db::getInstance()->getValue('SELECT `id_reference` FROM `'._DB_PREFIX_.$this->table.'` WHERE id_carrier = '.$oldId);
+		Db::getInstance()->Execute('UPDATE `'._DB_PREFIX_.$this->table.'`
+			SET `id_reference` = '.$id_reference.'
+			WHERE `id_carrier` = '.$this->id);
 	}
 
+	/**
+	 * Get carrier using the reference id
+	 */
+	public static function getCarrierByReference($id_reference)
+	{
+		// @todo class var $table must became static. here I have to use 'carrier' because this method is static
+		$id_carrier = Db::getInstance()->getValue('SELECT `id_carrier` FROM `'._DB_PREFIX_.'carrier`
+			WHERE id_reference = '.(int)$id_reference.' AND deleted = 0 ORDER BY id_carrier DESC');
+		if (!$id_carrier)
+			return false;
+		return new Carrier($id_carrier);
+	}
+	
 	/**
 	 * Check if carrier is used (at least one order placed)
 	 *
@@ -734,7 +758,7 @@ class CarrierCore extends ObjectModel
 		$shippingMethod = $this->getShippingMethod();
 		if ($shippingMethod == Carrier::SHIPPING_METHOD_WEIGHT)
 			return 'range_weight';
-		elseif ($shippingMethod == Carrier::SHIPPING_METHOD_PRICE)
+		else if ($shippingMethod == Carrier::SHIPPING_METHOD_PRICE)
 			return 'range_price';
 		return false;
 	}
@@ -744,7 +768,7 @@ class CarrierCore extends ObjectModel
 		$shippingMethod = $this->getShippingMethod();
 		if ($shippingMethod == Carrier::SHIPPING_METHOD_WEIGHT)
 			return new RangeWeight();
-		elseif ($shippingMethod == Carrier::SHIPPING_METHOD_PRICE)
+		else if ($shippingMethod == Carrier::SHIPPING_METHOD_PRICE)
 			return new RangePrice();
 		return false;
 	}
@@ -767,9 +791,9 @@ class CarrierCore extends ObjectModel
 			 SELECT `id_tax_rules_group`
 			 FROM `'._DB_PREFIX_.'carrier`
 			 WHERE `id_carrier` = '.(int)$id_carrier);
-	   }
+		}
 
-	   return self::$_cache_tax_rule[$id_carrier];
+		return self::$_cache_tax_rule[$id_carrier];
 	}
 
 
diff --git a/install-dev/sql/db.sql b/install-dev/sql/db.sql
index 944f0beb2..c1321686e 100644
--- a/install-dev/sql/db.sql
+++ b/install-dev/sql/db.sql
@@ -124,6 +124,7 @@ CREATE TABLE `PREFIX_attribute_lang` (
 
 CREATE TABLE `PREFIX_carrier` (
   `id_carrier` int(10) unsigned NOT NULL AUTO_INCREMENT,
+  `id_reference` int(10) unsigned NOT NULL,
   `id_tax_rules_group` int(10) unsigned DEFAULT '0',
   `name` varchar(64) NOT NULL,
   `url` varchar(255) DEFAULT NULL,
diff --git a/install-dev/sql/db_settings_extends.sql b/install-dev/sql/db_settings_extends.sql
index 84da2456e..c98356f9a 100644
--- a/install-dev/sql/db_settings_extends.sql
+++ b/install-dev/sql/db_settings_extends.sql
@@ -1,7 +1,7 @@
 SET NAMES 'utf8';
 
 /* Carrier */
-INSERT INTO `PREFIX_carrier` (`id_carrier`, `id_tax_rules_group`, `name`, `active`, `deleted`, `shipping_handling`, `is_free`) VALUES (2, 1, 'My carrier', 1, 0, 1, 0);
+INSERT INTO `PREFIX_carrier` (`id_carrier`, `id_reference`, `id_tax_rules_group`, `name`, `active`, `deleted`, `shipping_handling`, `is_free`) VALUES (2, 2, 1, 'My carrier', 1, 0, 1, 0);
 INSERT INTO `PREFIX_carrier_group` (`id_carrier`, `id_group`) VALUES (2, 1);
 INSERT INTO `PREFIX_carrier_shop` (`id_carrier`, `id_shop`) VALUES (2, 1);
 INSERT INTO `PREFIX_carrier_lang` (`id_carrier`, `id_lang`, `delay`) VALUES (2, 1, 'Delivery next day!'),(2, 2, 'Livraison le lendemain !'),(2, 3, '¡Entrega día siguiente!'),(2, 4, 'Zustellung am nächsten Tag!'),(2, 5, 'Consegna il giorno dopo!');
diff --git a/install-dev/sql/db_settings_lite.sql b/install-dev/sql/db_settings_lite.sql
index b768e4db6..08deee5bf 100644
--- a/install-dev/sql/db_settings_lite.sql
+++ b/install-dev/sql/db_settings_lite.sql
@@ -1160,7 +1160,7 @@ INSERT INTO `PREFIX_cms_category_lang` (`id_cms_category`, `id_lang`, `name`, `d
 INSERT INTO `PREFIX_cms_category` (`id_cms_category`, `id_parent`, `level_depth`, `active`, `date_add`, `date_upd`) VALUES(1, 0, 0, 1, NOW(), NOW());
 
 /* Carrier */
-INSERT INTO `PREFIX_carrier` (`id_carrier`, `id_tax_rules_group`, `name`, `active`, `deleted`, `shipping_handling`) VALUES (1, 0, 0, 1, 0, 0);
+INSERT INTO `PREFIX_carrier` (`id_carrier`, `id_reference`, `id_tax_rules_group`, `name`, `active`, `deleted`, `shipping_handling`) VALUES (1, 1, 0, 0, 1, 0, 0);
 
 INSERT INTO `PREFIX_carrier_group` (`id_carrier`, `id_group`) VALUES (1, 1);
 
diff --git a/install-dev/sql/upgrade/1.5.0.1.sql b/install-dev/sql/upgrade/1.5.0.1.sql
index 7d8f92220..29b169fed 100644
--- a/install-dev/sql/upgrade/1.5.0.1.sql
+++ b/install-dev/sql/upgrade/1.5.0.1.sql
@@ -170,3 +170,7 @@ CREATE TABLE IF NOT EXISTS `PREFIX_request_sql` (
 ) ENGINE=ENGINE_TYPE  DEFAULT CHARSET=utf8;
 
 /* PHP:add_new_tab(AdminRequestSql, fr:SQL Manager|es:SQL Manager|en:SQL Manager|de:Wunsh|it:SQL Manager, 9); */;
+
+
+ALTER TABLE `PREFIX_carrier` ADD COLUMN `id_reference` int(10)  NOT NULL AFTER `id_carrier`;
+UPDATE `PREFIX_carrier` SET id_reference = id_carrier;
\ No newline at end of file