diff --git a/classes/Carrier.php b/classes/Carrier.php
index 0b163b0e9..1d0c7c092 100644
--- a/classes/Carrier.php
+++ b/classes/Carrier.php
@@ -469,12 +469,11 @@ class CarrierCore extends ObjectModel
 		return Db::getInstance()->getValue('
 					SELECT id_tax_rules_group
 					FROM (
-						SELECT COUNT(*) n, carrier_shop.id_tax_rules_group
+						SELECT COUNT(*) n, c.id_tax_rules_group
 						FROM '._DB_PREFIX_.'carrier c
-						'.Shop::addSqlAssociation('carrier', 'c').'
-						JOIN '._DB_PREFIX_.'tax_rules_group trg ON (carrier_shop.id_tax_rules_group = trg.id_tax_rules_group)
+						JOIN '._DB_PREFIX_.'tax_rules_group trg ON (c.id_tax_rules_group = trg.id_tax_rules_group)
 						WHERE trg.active = 1
-						GROUP BY carrier.id_tax_rules_group
+						GROUP BY c.id_tax_rules_group
 						ORDER BY n DESC
 						LIMIT 1
 					) most_used'
diff --git a/controllers/admin/AdminCarrierWizardController.php b/controllers/admin/AdminCarrierWizardController.php
index 8b8cbabe3..bda129b4e 100644
--- a/controllers/admin/AdminCarrierWizardController.php
+++ b/controllers/admin/AdminCarrierWizardController.php
@@ -472,9 +472,11 @@ class AdminCarrierWizardControllerCore extends AdminController
 
 	public function getStepThreeFieldsValues($carrier)
 	{
+		$id_tax_rules_group = (is_object($this->object) && !$this->object->id) ? Carrier::getIdTaxRulesGroupMostUsed() : $this->getFieldValue($carrier, 'id_tax_rules_group');
+		
 		return array(
 			'is_free' => $this->getFieldValue($carrier, 'is_free'),
-			'id_tax_rules_group' => $this->getFieldValue($carrier, 'id_tax_rules_group'),
+			'id_tax_rules_group' => (int)$id_tax_rules_group,
 			'shipping_handling' => $this->getFieldValue($carrier, 'shipping_handling'),
 			'shipping_method' => $this->getFieldValue($carrier, 'shipping_method'),
 			'range_behavior' =>  $this->getFieldValue($carrier, 'range_behavior'),