diff --git a/core/class/declarationtva.class.php b/core/class/declarationtva.class.php
index 3548678..66c5d2d 100644
--- a/core/class/declarationtva.class.php
+++ b/core/class/declarationtva.class.php
@@ -335,6 +335,26 @@ class DeclarationTVA
         return true;
     }
 
+    /**
+     * Round VAT amount to whole number and format with original amount in brackets
+     *
+     * @param float $amount Original amount
+     * @return array Array with 'rounded' and 'formatted' values
+     */
+    private function roundVATAmount($amount)
+    {
+        $rounded = round($amount);
+        $formatted = $rounded;
+        if ($rounded != $amount) {
+            $formatted = $rounded . ' (' . number_format($amount, 2) . ')';
+        }
+        
+        return array(
+            'rounded' => $rounded,
+            'formatted' => $formatted
+        );
+    }
+
     /**
      * Calculate line 23: Subtotal of lines 20, 21, 22 (for user reference)
      *
@@ -528,11 +548,22 @@ class DeclarationTVA
      */
     public function createCA3Line($declaration_id, $ca3_line, $line_label, $amounts)
     {
+        // Round amounts to whole numbers
+        $rounded_base = round($amounts['base_amount']);
+        $rounded_vat = round($amounts['vat_amount']);
+        $rounded_total = round($amounts['total_amount']);
+        
+        // Create formatted label with original amounts in brackets if different
+        $formatted_label = $line_label;
+        if ($rounded_vat != $amounts['vat_amount']) {
+            $formatted_label .= ' [Original: ' . number_format($amounts['vat_amount'], 2) . ']';
+        }
+        
         $sql = "INSERT INTO " . MAIN_DB_PREFIX . "declarationtva_ca3_lines 
                 (declaration_id, ca3_line, line_label, base_amount, vat_amount, total_amount, created_date) 
                 VALUES (" . $declaration_id . ", '" . $this->db->escape($ca3_line) . "', 
-                '" . $this->db->escape($line_label) . "', " . $amounts['base_amount'] . ", 
-                " . $amounts['vat_amount'] . ", " . $amounts['total_amount'] . ", NOW())";
+                '" . $this->db->escape($formatted_label) . "', " . $rounded_base . ", 
+                " . $rounded_vat . ", " . $rounded_total . ", NOW())";
 
         $result = $this->db->query($sql);
         return $result !== false;
@@ -550,11 +581,17 @@ class DeclarationTVA
      */
     public function updateDeclarationTotals($declaration_id, $total_vat_collected, $total_vat_deductible, $net_vat_due, $vat_credit)
     {
+        // Round totals to whole numbers
+        $rounded_collected = round($total_vat_collected);
+        $rounded_deductible = round($total_vat_deductible);
+        $rounded_net_due = round($net_vat_due);
+        $rounded_credit = round($vat_credit);
+        
         $sql = "UPDATE " . MAIN_DB_PREFIX . "declarationtva_declarations 
-                SET total_vat_collected = " . $total_vat_collected . ", 
-                    total_vat_deductible = " . $total_vat_deductible . ", 
-                    net_vat_due = " . $net_vat_due . ", 
-                    vat_credit = " . $vat_credit . " 
+                SET total_vat_collected = " . $rounded_collected . ", 
+                    total_vat_deductible = " . $rounded_deductible . ", 
+                    net_vat_due = " . $rounded_net_due . ", 
+                    vat_credit = " . $rounded_credit . " 
                 WHERE rowid = " . $declaration_id;
 
         $result = $this->db->query($sql);