diff --git a/core/class/declarationtva.class.php b/core/class/declarationtva.class.php
index ba786a0..99e918b 100644
--- a/core/class/declarationtva.class.php
+++ b/core/class/declarationtva.class.php
@@ -263,6 +263,12 @@ class DeclarationTVA
             );
             
             $combined_label = !empty($account_labels) ? implode(', ', $account_labels) : 'No accounts mapped';
+            
+            // Truncate label if too long to prevent database issues (keep some buffer)
+            if (strlen($combined_label) > 1000) {
+                $combined_label = substr($combined_label, 0, 997) . '...';
+            }
+            
             $this->createCA3Line($declaration_id, $ca3_line, $combined_label, $combined_amounts);
             
             // Log the final amounts for debugging
diff --git a/sql/migration_fix_line_label_length.sql b/sql/migration_fix_line_label_length.sql
new file mode 100644
index 0000000..448ff28
--- /dev/null
+++ b/sql/migration_fix_line_label_length.sql
@@ -0,0 +1,11 @@
+-- Migration to fix line_label field length issue
+-- The varchar(255) limit was causing problems with many account mappings
+-- This increases it to TEXT to handle long account label combinations
+
+-- Update the line_label field to TEXT to handle long account combinations
+ALTER TABLE `llx_declarationtva_ca3_lines` 
+MODIFY COLUMN `line_label` TEXT DEFAULT NULL;
+
+-- Add comment to document the change
+ALTER TABLE `llx_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)';