diff --git a/htdocs/compta/facture/card.php b/htdocs/compta/facture/card.php
index 6c670b38406..c8c5822bb19 100644
--- a/htdocs/compta/facture/card.php
+++ b/htdocs/compta/facture/card.php
@@ -875,11 +875,29 @@ if (empty($reshook)) {
 				if ($line->product_type < 9 && $line->total_ht != 0) { // Remove lines with product_type greater than or equal to 9 and no need to create discount if amount is null
 					$keyforvatrate = $line->tva_tx.($line->vat_src_code ? ' ('.$line->vat_src_code.')' : '');
 
+					if (!isset($amount_ht[$keyforvatrate])) {
+						$amount_ht[$keyforvatrate]=0;
+					}
 					$amount_ht[$keyforvatrate] += $line->total_ht;
+					if (!isset($amount_tva[$keyforvatrate])) {
+						$amount_tva[$keyforvatrate]=0;
+					}
 					$amount_tva[$keyforvatrate] += $line->total_tva;
+					if (!isset($amount_ttc[$keyforvatrate])) {
+						$amount_ttc[$keyforvatrate]=0;
+					}
 					$amount_ttc[$keyforvatrate] += $line->total_ttc;
+					if (!isset($multicurrency_amount_ht[$keyforvatrate])) {
+						$multicurrency_amount_ht[$keyforvatrate]=0;
+					}
 					$multicurrency_amount_ht[$keyforvatrate] += $line->multicurrency_total_ht;
+					if (!isset($multicurrency_amount_tva[$keyforvatrate])) {
+						$multicurrency_amount_tva[$keyforvatrate]=0;
+					}
 					$multicurrency_amount_tva[$keyforvatrate] += $line->multicurrency_total_tva;
+					if (!isset($multicurrency_amount_ttc[$keyforvatrate])) {
+						$multicurrency_amount_ttc[$keyforvatrate]=0;
+					}
 					$multicurrency_amount_ttc[$keyforvatrate] += $line->multicurrency_total_ttc;
 					$i++;
 				}
diff --git a/htdocs/core/lib/functionsnumtoword.lib.php b/htdocs/core/lib/functionsnumtoword.lib.php
index f349368078a..b724ef34594 100644
--- a/htdocs/core/lib/functionsnumtoword.lib.php
+++ b/htdocs/core/lib/functionsnumtoword.lib.php
@@ -51,7 +51,7 @@ function dol_convertToWord($num, $langs, $currency = '', $centimes = false)
 	} else {
 		$TNum = explode('.', (string) $num);
 
-		$num = (int) $TNum[0];
+		$num = abs((int) $TNum[0]);
 		$words = array();
 		$list1 = array(
 			'',