diff --git a/admin/setup_mvp.php b/admin/setup_mvp.php
index 8af718c..f470554 100644
--- a/admin/setup_mvp.php
+++ b/admin/setup_mvp.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * MVP Setup page for DeclarationTVA module
- * Updated for Notice 4722 - Latest Official CA-3 Structure (3310-CA3-SD)
+ * Multi-select PCG account mapping using Dolibarr native style
  */
 
 // Load Dolibarr environment
@@ -37,10 +37,10 @@ if ($action == 'update_mappings') {
     $ca3_definitions = $config->getCA3LineDefinitions();
     
     foreach ($ca3_definitions as $line => $definition) {
-        $account_code = GETPOST('account_code_' . $line, 'alpha');
+        $account_codes = GETPOST('account_codes_' . $line, 'array');
         
-        if (!empty($account_code)) {
-            $config->updateAccountMapping($line, $account_code, '', '');
+        if (!empty($account_codes)) {
+            $config->updateAccountMapping($line, $account_codes);
         }
     }
     
@@ -48,13 +48,7 @@ if ($action == 'update_mappings') {
 }
 
 // Get current mappings
-$mappings = $config->getAllAccountMappings();
-$account_mappings = array();
-foreach ($mappings as $mapping) {
-    $account_mappings[$mapping['ca3_line']] = $mapping;
-}
-
-// Get available accounting accounts
+$mappings_by_line = $config->getAccountMappingsByLine();
 $accounts = $config->getAccountingAccounts();
 $ca3_definitions = $config->getCA3LineDefinitions();
 $section_headers = $config->getCA3SectionHeaders();
@@ -106,11 +100,11 @@ foreach ($lines_by_section as $section_code => $lines) {
     print '<th>' . $langs->trans("LineLabel") . '</th>';
     print '<th>' . $langs->trans("Description") . '</th>';
     print '<th>' . $langs->trans("PCGAccounts") . '</th>';
-    print '<th>' . $langs->trans("AccountCode") . '</th>';
+    print '<th>' . $langs->trans("AccountSelection") . '</th>';
     print '</tr>';
 
     foreach ($lines as $line => $definition) {
-        $mapping = isset($account_mappings[$line]) ? $account_mappings[$line] : array();
+        $selected_accounts = isset($mappings_by_line[$line]) ? $mappings_by_line[$line] : array();
         
         print '<tr>';
         print '<td><strong>' . $line . '</strong></td>';
@@ -118,13 +112,23 @@ foreach ($lines_by_section as $section_code => $lines) {
         print '<td><small>' . $definition['description'] . '</small></td>';
         print '<td><small>' . $definition['pcg_accounts'] . '</small></td>';
         print '<td>';
-        print '<select name="account_code_' . $line . '" class="flat">';
-        print '<option value="">' . $langs->trans("SelectAccount") . '</option>';
+        
+        // Create multi-select field using Dolibarr style
+        $account_options = array();
         foreach ($accounts as $account) {
-            $selected = (isset($mapping['account_code']) && $mapping['account_code'] == $account['account_number']) ? 'selected' : '';
-            print '<option value="' . $account['account_number'] . '" ' . $selected . '>' . $account['account_number'] . ' - ' . $account['label'] . '</option>';
+            $account_options[$account['account_number']] = $account['account_number'] . ' - ' . $account['label'];
+        }
+        
+        // Use Dolibarr's native multi-select style
+        print '<select name="account_codes_' . $line . '[]" class="flat" multiple size="3" style="min-width: 300px;">';
+        foreach ($account_options as $account_code => $account_label) {
+            $selected = in_array($account_code, $selected_accounts) ? 'selected' : '';
+            print '<option value="' . $account_code . '" ' . $selected . '>' . $account_label . '</option>';
         }
         print '</select>';
+        
+        // Add helper text
+        print '<br><small>' . $langs->trans("MultiSelectHelp") . '</small>';
         print '</td>';
         print '</tr>';
     }
@@ -143,19 +147,18 @@ print '</form>';
 print '<div class="fiche">';
 print '<div class="titre">' . $langs->trans("CurrentConfiguration") . '</div>';
 
-if (empty($mappings)) {
+if (empty($mappings_by_line)) {
     print '<div class="info">' . $langs->trans("NoConfigurationFound") . '</div>';
 } else {
     // Group by section for display
     $mappings_by_section = array();
-    foreach ($mappings as $mapping) {
-        $line = $mapping['ca3_line'];
+    foreach ($mappings_by_line as $line => $account_codes) {
         if (isset($ca3_definitions[$line])) {
             $section = $ca3_definitions[$line]['section'];
             if (!isset($mappings_by_section[$section])) {
                 $mappings_by_section[$section] = array();
             }
-            $mappings_by_section[$section][] = $mapping;
+            $mappings_by_section[$section][$line] = $account_codes;
         }
     }
     
@@ -167,15 +170,15 @@ if (empty($mappings)) {
         print '<table class="noborder centpercent">';
         print '<tr class="liste_titre">';
         print '<th>' . $langs->trans("CA3Line") . '</th>';
-        print '<th>' . $langs->trans("AccountCode") . '</th>';
-        print '<th>' . $langs->trans("Status") . '</th>';
+        print '<th>' . $langs->trans("SelectedAccounts") . '</th>';
+        print '<th>' . $langs->trans("AccountCount") . '</th>';
         print '</tr>';
 
-        foreach ($section_mappings as $mapping) {
+        foreach ($section_mappings as $line => $account_codes) {
             print '<tr>';
-            print '<td><strong>' . $mapping['ca3_line'] . '</strong></td>';
-            print '<td>' . $mapping['account_code'] . '</td>';
-            print '<td>' . ($mapping['is_active'] ? $langs->trans("Active") : $langs->trans("Inactive")) . '</td>';
+            print '<td><strong>' . $line . '</strong></td>';
+            print '<td>' . implode(', ', $account_codes) . '</td>';
+            print '<td>' . count($account_codes) . '</td>';
             print '</tr>';
         }
         print '</table>';
diff --git a/core/class/declarationtva_config.class.php b/core/class/declarationtva_config.class.php
index ea6edb4..6049963 100644
--- a/core/class/declarationtva_config.class.php
+++ b/core/class/declarationtva_config.class.php
@@ -94,28 +94,36 @@ class DeclarationTVA_Config
     }
 
     /**
-     * Update account mapping
+     * Update account mapping for multiple accounts
      *
      * @param string $ca3_line CA-3 line code
-     * @param string $account_code Account code
-     * @param string $account_label Account label
-     * @param float $vat_rate VAT rate
+     * @param array $account_codes Array of account codes
      * @return bool Success
      */
-    public function updateAccountMapping($ca3_line, $account_code, $account_label, $vat_rate)
+    public function updateAccountMapping($ca3_line, $account_codes)
     {
-        $sql = "INSERT INTO " . MAIN_DB_PREFIX . "declarationtva_account_mappings 
-                (entity, ca3_line, account_code, account_label, vat_rate, is_active, created_date) 
-                VALUES (" . $this->entity . ", '" . $this->db->escape($ca3_line) . "', 
-                '" . $this->db->escape($account_code) . "', '" . $this->db->escape($account_label) . "', 
-                " . $vat_rate . ", 1, NOW()) 
-                ON DUPLICATE KEY UPDATE 
-                account_code = '" . $this->db->escape($account_code) . "', 
-                account_label = '" . $this->db->escape($account_label) . "', 
-                vat_rate = " . $vat_rate;
-
-        $result = $this->db->query($sql);
-        return $result !== false;
+        // First, deactivate all existing mappings for this CA-3 line
+        $sql = "UPDATE " . MAIN_DB_PREFIX . "declarationtva_account_mappings 
+                SET is_active = 0 
+                WHERE entity = " . $this->entity . " AND ca3_line = '" . $this->db->escape($ca3_line) . "'";
+        $this->db->query($sql);
+        
+        // Then insert/activate new mappings
+        if (!empty($account_codes)) {
+            foreach ($account_codes as $account_code) {
+                if (!empty($account_code)) {
+                    $sql = "INSERT INTO " . MAIN_DB_PREFIX . "declarationtva_account_mappings 
+                            (entity, ca3_line, account_code, account_label, vat_rate, is_active, created_date) 
+                            VALUES (" . $this->entity . ", '" . $this->db->escape($ca3_line) . "', 
+                            '" . $this->db->escape($account_code) . "', '', 0, 1, NOW()) 
+                            ON DUPLICATE KEY UPDATE 
+                            is_active = 1, account_code = '" . $this->db->escape($account_code) . "'";
+                    $this->db->query($sql);
+                }
+            }
+        }
+        
+        return true;
     }
 
     /**
@@ -148,6 +156,32 @@ class DeclarationTVA_Config
         return $mappings;
     }
 
+    /**
+     * Get account mappings grouped by CA-3 line
+     *
+     * @return array Account mappings grouped by CA-3 line
+     */
+    public function getAccountMappingsByLine()
+    {
+        $sql = "SELECT ca3_line, account_code FROM " . MAIN_DB_PREFIX . "declarationtva_account_mappings 
+                WHERE entity = " . $this->entity . " AND is_active = 1 
+                ORDER BY ca3_line, account_code";
+
+        $result = $this->db->query($sql);
+        $mappings = array();
+
+        if ($result) {
+            while ($obj = $this->db->fetch_object($result)) {
+                if (!isset($mappings[$obj->ca3_line])) {
+                    $mappings[$obj->ca3_line] = array();
+                }
+                $mappings[$obj->ca3_line][] = $obj->account_code;
+            }
+        }
+
+        return $mappings;
+    }
+
     /**
      * Get available accounting accounts from Dolibarr
      *
diff --git a/langs/en_US/declarationtva.lang b/langs/en_US/declarationtva.lang
index 2b7d25e..cec0999 100644
--- a/langs/en_US/declarationtva.lang
+++ b/langs/en_US/declarationtva.lang
@@ -365,3 +365,7 @@ CA3Line29 = VAT credit to carry forward or refund
 # Form Labels
 Description = Description
 PCGAccounts = PCG Accounts
+AccountSelection = Account Selection
+SelectedAccounts = Selected Accounts
+AccountCount = Account Count
+MultiSelectHelp = Hold Ctrl (or Cmd on Mac) to select multiple accounts
diff --git a/langs/fr_FR/declarationtva.lang b/langs/fr_FR/declarationtva.lang
index a60dcda..6af63b9 100644
--- a/langs/fr_FR/declarationtva.lang
+++ b/langs/fr_FR/declarationtva.lang
@@ -354,3 +354,7 @@ CA3Line29 = Crédit de TVA à reporter ou remboursement
 # Labels de formulaire
 Description = Description
 PCGAccounts = Comptes PCG
+AccountSelection = Sélection de comptes
+SelectedAccounts = Comptes sélectionnés
+AccountCount = Nombre de comptes
+MultiSelectHelp = Maintenez Ctrl (ou Cmd sur Mac) pour sélectionner plusieurs comptes