diff --git a/migrate_line_label_field.php b/migrate_line_label_field.php
new file mode 100644
index 0000000..8c48251
--- /dev/null
+++ b/migrate_line_label_field.php
@@ -0,0 +1,78 @@
+<?php
+/**
+ * Database Migration Script for DeclarationTVA Module
+ * 
+ * This script migrates the line_label field from varchar(255) to TEXT
+ * to handle long account label combinations with many mapped accounts.
+ * 
+ * Run this script through your web browser to apply the migration.
+ */
+
+// Include Dolibarr main file
+require_once '../../main.inc.php';
+
+// Check if user has admin rights
+if (!$user->admin) {
+    die("Access denied. Admin rights required.");
+}
+
+// Set page title
+$title = "DeclarationTVA - Database Migration";
+$mainmenu = "home";
+$leftmenu = "home";
+
+// Include Dolibarr header
+llxHeader($title, $mainmenu, $leftmenu);
+
+print '<div class="fichecenter">';
+print '<div class="fichehalfleft">';
+print '<div class="titre">DeclarationTVA Database Migration</div>';
+
+// Check if migration has already been applied
+$sql_check = "SHOW COLUMNS FROM " . MAIN_DB_PREFIX . "declarationtva_ca3_lines LIKE 'line_label'";
+$result_check = $db->query($sql_check);
+
+if ($result_check) {
+    $obj_check = $db->fetch_object($result_check);
+    if ($obj_check && strpos($obj_check->Type, 'text') !== false) {
+        print '<div class="info">';
+        print '<strong>Migration already applied!</strong><br>';
+        print 'The line_label field is already TEXT type. No migration needed.';
+        print '</div>';
+    } else {
+        // Apply the migration
+        print '<div class="info">';
+        print '<strong>Applying migration...</strong><br>';
+        
+        $sql_migration = "ALTER TABLE `" . MAIN_DB_PREFIX . "declarationtva_ca3_lines` 
+                         MODIFY COLUMN `line_label` TEXT DEFAULT NULL 
+                         COMMENT 'Combined account labels for this CA-3 line (can be long with many accounts)'";
+        
+        $result_migration = $db->query($sql_migration);
+        
+        if ($result_migration) {
+            print '<div class="ok">';
+            print '<strong>Migration successful!</strong><br>';
+            print 'The line_label field has been changed from varchar(255) to TEXT.<br>';
+            print 'You can now recalculate your declarations to see the full account labels.';
+            print '</div>';
+        } else {
+            print '<div class="error">';
+            print '<strong>Migration failed!</strong><br>';
+            print 'Error: ' . $db->lasterror();
+            print '</div>';
+        }
+    }
+} else {
+    print '<div class="error">';
+    print '<strong>Error checking current field type!</strong><br>';
+    print 'Error: ' . $db->lasterror();
+    print '</div>';
+}
+
+print '</div>';
+print '</div>';
+
+// Include Dolibarr footer
+llxFooter();
+?>