diff --git a/htdocs/comm/propal.php b/htdocs/comm/propal.php
index a8c268ccfee..86a7c6526ba 100644
--- a/htdocs/comm/propal.php
+++ b/htdocs/comm/propal.php
@@ -634,7 +634,7 @@ else if ($action == "addline" && $user->rights->propal->creer)
 	$idprod=GETPOST('idprod', 'int');
 	$product_desc = (GETPOST('product_desc')?GETPOST('product_desc'):(GETPOST('np_desc')?GETPOST('np_desc'):(GETPOST('dp_desc')?GETPOST('dp_desc'):'')));
 	$price_ht = GETPOST('price_ht');
-	$tva_tx = GETPOST('tva_tx');
+	$tva_tx = (GETPOST('tva_tx')?GETPOST('tva_tx'):0);
 
 	if (empty($idprod) && GETPOST('type') < 0)
 	{
@@ -844,7 +844,7 @@ else if ($action == 'updateligne' && $user->rights->propal->creer && GETPOST('sa
 	$description=dol_htmlcleanlastbr(GETPOST('product_desc'));
 
 	// Define vat_rate
-	$vat_rate=GETPOST('tva_tx');
+	$vat_rate=(GETPOST('tva_tx')?GETPOST('tva_tx'):0);
 	$vat_rate=str_replace('*','',$vat_rate);
 	$localtax1_rate=get_localtax($vat_rate,1,$object->client);
 	$localtax2_rate=get_localtax($vat_rate,2,$object->client);
diff --git a/htdocs/commande/fiche.php b/htdocs/commande/fiche.php
index 167f4c53268..a1e9acf3607 100644
--- a/htdocs/commande/fiche.php
+++ b/htdocs/commande/fiche.php
@@ -537,7 +537,7 @@ else if ($action == 'addline' && $user->rights->commande->creer)
 	$idprod=GETPOST('idprod', 'int');
 	$product_desc = (GETPOST('product_desc')?GETPOST('product_desc'):(GETPOST('np_desc')?GETPOST('np_desc'):(GETPOST('dp_desc')?GETPOST('dp_desc'):'')));
 	$price_ht = GETPOST('price_ht');
-	$tva_tx = GETPOST('tva_tx');
+	$tva_tx = (GETPOST('tva_tx')?GETPOST('tva_tx'):0);
 
 	if ((empty($idprod) || GETPOST('usenewaddlineform')) && ($price_ht < 0) && (GETPOST('qty') < 0))
     {
@@ -767,13 +767,13 @@ else if ($action == 'updateligne' && $user->rights->commande->creer && GETPOST('
 	$date_end=dol_mktime(0, 0, 0, GETPOST('date_endmonth'), GETPOST('date_endday'), GETPOST('date_endyear'));
 	$description=dol_htmlcleanlastbr(GETPOST('product_desc'));
 	$pu_ht=GETPOST('price_ht');
+	$vat_rate=(GETPOST('tva_tx')?GETPOST('tva_tx'):0);
 
 	// Define info_bits
 	$info_bits=0;
-	if (preg_match('/\*/', GETPOST('tva_tx'))) $info_bits |= 0x01;
+	if (preg_match('/\*/', $vat_rate)) $info_bits |= 0x01;
 
 	// Define vat_rate
-	$vat_rate=GETPOST('tva_tx');
 	$vat_rate=str_replace('*','',$vat_rate);
 	$localtax1_rate=get_localtax($vat_rate,1,$object->client);
 	$localtax2_rate=get_localtax($vat_rate,2,$object->client);
diff --git a/htdocs/compta/facture.php b/htdocs/compta/facture.php
index 809bd6eb452..75a67be6bff 100644
--- a/htdocs/compta/facture.php
+++ b/htdocs/compta/facture.php
@@ -965,7 +965,7 @@ else if (($action == 'addline' || $action == 'addline_predef') && $user->rights-
     $idprod=GETPOST('idprod', 'int');
 	$product_desc = (GETPOST('product_desc')?GETPOST('product_desc'):(GETPOST('np_desc')?GETPOST('np_desc'):(GETPOST('dp_desc')?GETPOST('dp_desc'):'')));
 	$price_ht = GETPOST('price_ht');
-	$tva_tx = GETPOST('tva_tx');
+	$tva_tx=(GETPOST('tva_tx')?GETPOST('tva_tx'):0);
 
 	if ((empty($idprod) || GETPOST('usenewaddlineform')) && ($price_ht < 0) && (GETPOST('qty') < 0))
     {
@@ -1220,13 +1220,13 @@ else if ($action == 'updateligne' && $user->rights->facture->creer && $_POST['sa
     $date_end=dol_mktime(GETPOST('date_endhour'), GETPOST('date_endmin'), GETPOST('date_endsec'), GETPOST('date_endmonth'), GETPOST('date_endday'), GETPOST('date_endyear'));
     $description=dol_htmlcleanlastbr(GETPOST('product_desc'));
     $pu_ht=GETPOST('price_ht');
+    $vat_rate=(GETPOST('tva_tx')?GETPOST('tva_tx'):0);
 
     // Define info_bits
     $info_bits=0;
-    if (preg_match('/\*/', GETPOST('tva_tx'))) $info_bits |= 0x01;
+    if (preg_match('/\*/', $vat_rate)) $info_bits |= 0x01;
 
     // Define vat_rate
-    $vat_rate=$_POST['tva_tx'];
     $vat_rate=str_replace('*','',$vat_rate);
     $localtax1_rate=get_localtax($vat_rate,1,$object->client);
     $localtax2_rate=get_localtax($vat_rate,2,$object->client);