diff --git a/classes/controllers/LengowOrderController.php b/classes/controllers/LengowOrderController.php
index b491178f..6ddf485e 100755
--- a/classes/controllers/LengowOrderController.php
+++ b/classes/controllers/LengowOrderController.php
@@ -152,16 +152,18 @@ public function postProcess()
                     break;
                 case 'save_shipping_method':
                     $idOrder = (int) Tools::getValue('id_order');
-                    $shippingMethod = Tools::getValue('method');
+                    $shippingMethod = Tools::getValue('method', null);
                     $response = ['success' => false, 'message' => ''];
 
-                    if (!$idOrder || !$shippingMethod) {
+                    if (!$idOrder) {
                         $response['message'] = 'Missing parameters';
                     } else {
                         try {
+                            // Allow empty string to clear the shipping method (saves NULL in DB)
+                            $methodValue = ($shippingMethod !== null && $shippingMethod !== '') ? pSQL($shippingMethod) : null;
                             $result = Db::getInstance()->update(
                                 'lengow_orders',
-                                ['method' => pSQL($shippingMethod)],
+                                ['method' => $methodValue],
                                 'id_order = ' . $idOrder
                             );
 
diff --git a/classes/models/LengowHook.php b/classes/models/LengowHook.php
index fd84ccfe..f8ac9ab8 100755
--- a/classes/models/LengowHook.php
+++ b/classes/models/LengowHook.php
@@ -334,11 +334,13 @@ public function hookAdminOrderSide($params)
         $shippingMethods = LengowMarketplace::getValidShippingMethods($marketplaceName);
 
         $ajaxUrl = $this->context->link->getAdminLink('AdminLengowOrder', true);
+        $locale = new LengowTranslation();
         $this->context->smarty->assign([
             'id_order' => $id_order,
             'shipping_methods' => $shippingMethods,
             'lengowOrder' => $lengowOrder,
             'ajax_url' => $ajaxUrl,
+            'lengow_locale' => $locale,
         ]);
 
         return $this->module->display(_PS_MODULE_LENGOW_DIR_, 'views/templates/hook/order/admin_order_side.tpl');
diff --git a/classes/models/LengowMarketplace.php b/classes/models/LengowMarketplace.php
index 797232a1..753654e2 100644
--- a/classes/models/LengowMarketplace.php
+++ b/classes/models/LengowMarketplace.php
@@ -505,7 +505,16 @@ protected function getAllParams($action, $lengowOrder, $marketplaceArguments)
                     $params[$arg] = $carrierName;
                     break;
                 case LengowAction::ARG_SHIPPING_METHOD:
-                    $params[$arg] = $shippingMethod;
+                    // Only send shipping_method when it is a required argument,
+                    // or when it is optional but has a non-empty value set by the merchant.
+                    // This prevents sending Amazon-imported default values (e.g. "Standard", "SecondDay")
+                    // when the merchant has not explicitly chosen a shipping method.
+                    $isRequired = isset($actions['args']) && in_array(LengowAction::ARG_SHIPPING_METHOD, $actions['args'], true);
+                    if ($isRequired) {
+                        $params[$arg] = $shippingMethod ?? '';
+                    } elseif (!empty($shippingMethod)) {
+                        $params[$arg] = $shippingMethod;
+                    }
                     break;
                 case LengowAction::ARG_RETURN_CARRIER:
                     $idReturnCarrier = LengowOrderDetail::getOrderReturnCarrier($lengowOrder->id);
diff --git a/translations/en.csv b/translations/en.csv
index 8871b4ee..9ec091ed 100755
--- a/translations/en.csv
+++ b/translations/en.csv
@@ -471,6 +471,14 @@ admin.order.resend_action|Resend Action
 admin.order.check_resend_action|Do you really want to send the following action: %{action}?
 admin.order.customer_shipping_phone|Customer shipping phone
 admin.order.customer_billing_phone|Customer billing phone
+admin.order.shipping_method_label|Shipping method sent by Lengow:
+admin.order.shipping_method_empty|-- No shipping method selected --
+admin.order.shipping_method_custom_label|Or enter a custom value (e.g. ECONOMY):
+admin.order.shipping_method_custom_help|The value entered here takes priority over the dropdown selection above. Amazon accepts free text values for this field.
+admin.order.shipping_method_save|Save shipping method
+admin.order.shipping_method_saved|Shipping method saved successfully.
+admin.order.shipping_method_error|Error:
+admin.order.shipping_method_server_error|Error communicating with server
 log.install.install_start|## start install for version %{version} ##
 log.install.install_end|## end install for version %{version} ##
 log.install.table_created|adding table %{name} in database
diff --git a/translations/es.csv b/translations/es.csv
index 975ad29f..3ed79ba7 100755
--- a/translations/es.csv
+++ b/translations/es.csv
@@ -471,3 +471,11 @@ admin.order.resend_action|Reenvie la accion
 admin.order.check_resend_action|¿Realmente desea enviar la siguiente acción: %{action} ?
 admin.order.customer_shipping_phone|Teléfono de envío al cliente
 admin.order.customer_billing_phone|Teléfono de facturación al cliente
+admin.order.shipping_method_label|Método de envío enviado por Lengow:
+admin.order.shipping_method_empty|-- Ningún método de envío seleccionado --
+admin.order.shipping_method_custom_label|O introduzca un valor personalizado (ej. ECONOMY):
+admin.order.shipping_method_custom_help|El valor introducido aquí tendrá prioridad sobre la selección del menú desplegable. Amazon acepta valores de texto libre para este campo.
+admin.order.shipping_method_save|Guardar método de envío
+admin.order.shipping_method_saved|Método de envío guardado correctamente.
+admin.order.shipping_method_error|Error:
+admin.order.shipping_method_server_error|Error de comunicación con el servidor
diff --git a/translations/fr.csv b/translations/fr.csv
index ade5a057..d7539dd7 100755
--- a/translations/fr.csv
+++ b/translations/fr.csv
@@ -471,3 +471,11 @@ admin.order.resend_action|Renvoyer l'action
 admin.order.check_resend_action|Vous voulez vous vraiment renvoyer l'action %{action} ?
 admin.order.customer_shipping_phone|Numéro de téléphone de livraison client
 admin.order.customer_billing_phone|Numéro de téléphone de facturation client
+admin.order.shipping_method_label|Méthode de livraison envoyée par Lengow :
+admin.order.shipping_method_empty|-- Aucune méthode de livraison sélectionnée --
+admin.order.shipping_method_custom_label|Ou saisissez une valeur personnalisée (ex : ECONOMY) :
+admin.order.shipping_method_custom_help|La valeur saisie ici sera prioritaire sur la sélection du menu déroulant ci-dessus. Amazon accepte des valeurs libres pour ce champ.
+admin.order.shipping_method_save|Enregistrer la méthode de livraison
+admin.order.shipping_method_saved|Méthode enregistrée avec succès.
+admin.order.shipping_method_error|Erreur :
+admin.order.shipping_method_server_error|Erreur de communication avec le serveur
diff --git a/translations/it.csv b/translations/it.csv
index ca465240..1d20dbd8 100755
--- a/translations/it.csv
+++ b/translations/it.csv
@@ -471,3 +471,11 @@ admin.order.resend_action|Re-invia Azione
 admin.order.check_resend_action|Vuoi veramente inviare di nuovo questa azione: %{action}?
 admin.order.customer_shipping_phone|Telefono per la spedizione del cliente
 admin.order.customer_billing_phone|Telefono per la fatturazione del cliente
+admin.order.shipping_method_label|Metodo di spedizione inviato da Lengow:
+admin.order.shipping_method_empty|-- Nessun metodo di spedizione selezionato --
+admin.order.shipping_method_custom_label|Oppure inserire un valore personalizzato (es. ECONOMY):
+admin.order.shipping_method_custom_help|Il valore inserito qui avrà la priorità sulla selezione del menu a discesa. Amazon accetta valori di testo libero per questo campo.
+admin.order.shipping_method_save|Salva metodo di spedizione
+admin.order.shipping_method_saved|Metodo di spedizione salvato con successo.
+admin.order.shipping_method_error|Errore:
+admin.order.shipping_method_server_error|Errore di comunicazione con il server
diff --git a/translations/yml/en.yml b/translations/yml/en.yml
index 188604d6..c873177d 100755
--- a/translations/yml/en.yml
+++ b/translations/yml/en.yml
@@ -510,3 +510,11 @@ en:
       check_resend_action: "Do you really want to send the following action: %{action}?"
       customer_shipping_phone: "Customer shipping phone"
       customer_billing_phone: "Customer billing phone"
+      shipping_method_label: "Shipping method sent by Lengow:"
+      shipping_method_empty: "-- No shipping method selected --"
+      shipping_method_custom_label: "Or enter a custom value (e.g. ECONOMY):"
+      shipping_method_custom_help: "The value entered here takes priority over the dropdown selection above. Amazon accepts free text values for this field."
+      shipping_method_save: "Save shipping method"
+      shipping_method_saved: "Shipping method saved successfully."
+      shipping_method_error: "Error:"
+      shipping_method_server_error: "Error communicating with server"
diff --git a/translations/yml/es.yml b/translations/yml/es.yml
index 7a79ab00..a5df6822 100755
--- a/translations/yml/es.yml
+++ b/translations/yml/es.yml
@@ -510,3 +510,11 @@ es:
       check_resend_action: "¿Realmente desea enviar la siguiente acción: %{action} ?"
       customer_shipping_phone: "Teléfono de envío al cliente"
       customer_billing_phone: "Teléfono de facturación al cliente"
+      shipping_method_label: "Método de envío enviado por Lengow:"
+      shipping_method_empty: "-- Ningún método de envío seleccionado --"
+      shipping_method_custom_label: "O introduzca un valor personalizado (ej. ECONOMY):"
+      shipping_method_custom_help: "El valor introducido aquí tendrá prioridad sobre la selección del menú desplegable. Amazon acepta valores de texto libre para este campo."
+      shipping_method_save: "Guardar método de envío"
+      shipping_method_saved: "Método de envío guardado correctamente."
+      shipping_method_error: "Error:"
+      shipping_method_server_error: "Error de comunicación con el servidor"
diff --git a/translations/yml/fr.yml b/translations/yml/fr.yml
index 201603b7..781697c5 100755
--- a/translations/yml/fr.yml
+++ b/translations/yml/fr.yml
@@ -510,3 +510,11 @@ fr:
       check_resend_action: "Vous voulez vous vraiment renvoyer l'action %{action} ?"
       customer_shipping_phone: "Numéro de téléphone de livraison client"
       customer_billing_phone: "Numéro de téléphone de facturation client"
+      shipping_method_label: "Méthode de livraison envoyée par Lengow :"
+      shipping_method_empty: "-- Aucune méthode de livraison sélectionnée --"
+      shipping_method_custom_label: "Ou saisissez une valeur personnalisée (ex : ECONOMY) :"
+      shipping_method_custom_help: "La valeur saisie ici sera prioritaire sur la sélection du menu déroulant ci-dessus. Amazon accepte des valeurs libres pour ce champ."
+      shipping_method_save: "Enregistrer la méthode de livraison"
+      shipping_method_saved: "Méthode enregistrée avec succès."
+      shipping_method_error: "Erreur :"
+      shipping_method_server_error: "Erreur de communication avec le serveur"
diff --git a/translations/yml/it.yml b/translations/yml/it.yml
index 73bc53b7..7b587fec 100755
--- a/translations/yml/it.yml
+++ b/translations/yml/it.yml
@@ -510,3 +510,11 @@ it:
       check_resend_action: "Vuoi veramente inviare di nuovo questa azione: %{action}?"
       customer_shipping_phone: "Telefono per la spedizione del cliente"
       customer_billing_phone: "Telefono per la fatturazione del cliente"
+      shipping_method_label: "Metodo di spedizione inviato da Lengow:"
+      shipping_method_empty: "-- Nessun metodo di spedizione selezionato --"
+      shipping_method_custom_label: "Oppure inserire un valore personalizzato (es. ECONOMY):"
+      shipping_method_custom_help: "Il valore inserito qui avrà la priorità sulla selezione del menu a discesa. Amazon accetta valori di testo libero per questo campo."
+      shipping_method_save: "Salva metodo di spedizione"
+      shipping_method_saved: "Metodo di spedizione salvato con successo."
+      shipping_method_error: "Errore:"
+      shipping_method_server_error: "Errore di comunicazione con il server"
diff --git a/views/templates/hook/order/admin_order_side.tpl b/views/templates/hook/order/admin_order_side.tpl
index 6eadd4d2..edbd979d 100644
--- a/views/templates/hook/order/admin_order_side.tpl
+++ b/views/templates/hook/order/admin_order_side.tpl
@@ -21,29 +21,58 @@
     <div class="card-header"><h2>Lengow Shipping</h2></div>
     <div class="card-body">
         <div class="form-group">
-            <label for="lengow_shipping_select">Méthode de livraison envoyée par Lengow :</label>
+            <label for="lengow_shipping_select">{$lengow_locale->t('admin.order.shipping_method_label')|escape:'html':'UTF-8'}</label>
             <select id="lengow_shipping_select" class="form-control">
+                <option value="">{$lengow_locale->t('admin.order.shipping_method_empty')|escape:'html':'UTF-8'}</option>
                 {foreach from=$shipping_methods item=method}
-                    {if $method.method_lengow_code}
+                    {if $method.method_lengow_code && $method.method_lengow_code !== 'null' && $method.method_lengow_code !== 'NULL'}
                         <option value="{$method.method_lengow_code|escape:'html':'UTF-8'}"
-                                {if isset($lengowOrder.method) && $lengowOrder.method == $method.method_lengow_code}selected{/if}>
+                                {if isset($lengowOrder.method) && $lengowOrder.method !== '' && $lengowOrder.method !== null && $lengowOrder.method == $method.method_lengow_code}selected{/if}>
                             {$method.method_lengow_code|escape:'html':'UTF-8'}
                         </option>
                     {/if}
                 {/foreach}
             </select>
         </div>
-        <button id="save_lengow_method" class="btn btn-primary mt-3">Enregistrer la méthode de livraison</button>
+        <div class="form-group mt-2">
+            <label for="lengow_shipping_custom">{$lengow_locale->t('admin.order.shipping_method_custom_label')|escape:'html':'UTF-8'}</label>
+            <input type="text" id="lengow_shipping_custom" class="form-control"
+                   placeholder="ECONOMY"
+                   value="{if isset($lengowOrder.method) && $lengowOrder.method !== '' && $lengowOrder.method !== null}{$lengowOrder.method|escape:'html':'UTF-8'}{/if}" />
+            <small class="form-text text-muted">
+                {$lengow_locale->t('admin.order.shipping_method_custom_help')|escape:'html':'UTF-8'}
+            </small>
+        </div>
+        <button id="save_lengow_method" class="btn btn-primary mt-3">{$lengow_locale->t('admin.order.shipping_method_save')|escape:'html':'UTF-8'}</button>
         <div id="lengow_save_result" class="mt-2"></div>
     </div>
 </div>
 
 <script>
     (function() {
+        var i18n = {
+            saved: "{$lengow_locale->t('admin.order.shipping_method_saved')|escape:'javascript':'UTF-8'}",
+            error: "{$lengow_locale->t('admin.order.shipping_method_error')|escape:'javascript':'UTF-8'}",
+            serverError: "{$lengow_locale->t('admin.order.shipping_method_server_error')|escape:'javascript':'UTF-8'}"
+        };
         document.addEventListener('DOMContentLoaded', function() {
+            var selectEl = document.getElementById('lengow_shipping_select');
+            var customEl = document.getElementById('lengow_shipping_custom');
+
+            // When a dropdown option is chosen, copy it to the text field (or clear if empty option)
+            selectEl.addEventListener('change', function() {
+                customEl.value = selectEl.value;
+            });
+
+            // When text field is modified, reset dropdown to empty
+            customEl.addEventListener('input', function() {
+                selectEl.value = '';
+            });
+
             var btn = document.getElementById('save_lengow_method');
             btn.addEventListener('click', function() {
-                var method = document.getElementById('lengow_shipping_select').value;
+                // Text field takes priority; otherwise use dropdown value
+                var method = customEl.value !== '' ? customEl.value : selectEl.value;
                 var idOrder = {$id_order|intval};
                 // URL générée par getAdminLink (inclut token et controller)
                 var url = "{$ajax_url|escape:'javascript':'UTF-8'}";
@@ -59,15 +88,15 @@
                     .then(function(json) {
                         var res = document.getElementById('lengow_save_result');
                         if (json.success) {
-                            res.innerHTML = '<div class="alert alert-success">Méthode enregistrée avec succès.</div>';
+                            res.innerHTML = '<div class="alert alert-success">' + i18n.saved + '</div>';
                             setTimeout(function() { res.innerHTML = ''; }, 5000);
                         } else {
-                            res.innerHTML = '<div class="alert alert-danger">Erreur : ' + json.message + '</div>';
+                            res.innerHTML = '<div class="alert alert-danger">' + i18n.error + ' ' + json.message + '</div>';
                         }
                     })
                     .catch(function(error) {
                         console.error(error);
-                        document.getElementById('lengow_save_result').innerHTML = '<div class="alert alert-danger">Erreur de communication avec le serveur</div>';
+                        document.getElementById('lengow_save_result').innerHTML = '<div class="alert alert-danger">' + i18n.serverError + '</div>';
                     });
             });
         });