diff --git a/htdocs/core/class/commoninvoice.class.php b/htdocs/core/class/commoninvoice.class.php
index b586c69d464..9bd14d120fe 100644
--- a/htdocs/core/class/commoninvoice.class.php
+++ b/htdocs/core/class/commoninvoice.class.php
@@ -1756,8 +1756,8 @@ abstract class CommonInvoice extends CommonObject
 		if ($this->ref_client) {
 			$complementaryinfo .= '/20/'.$this->ref_client;
 		}
-		if ($this->thirdparty->vat_number) {
-			$complementaryinfo .= '/30/'.$this->thirdparty->vat_number;
+		if ($this->thirdparty->tva_intra) {
+			$complementaryinfo .= '/30/'.$this->thirdparty->tva_intra;
 		}
 
 		// Header