diff --git a/htdocs/compta/prelevement/class/bonprelevement.class.php b/htdocs/compta/prelevement/class/bonprelevement.class.php
index a1dcdba6f58..fd9575dd982 100644
--- a/htdocs/compta/prelevement/class/bonprelevement.class.php
+++ b/htdocs/compta/prelevement/class/bonprelevement.class.php
@@ -1709,7 +1709,7 @@ class BonPrelevement extends CommonObject
 	{
 		global $langs;
 		$pre = substr(dol_string_nospecial(dol_string_unaccent($langs->transnoentitiesnoconv('RUM'))), 0, 3); // Must always be on 3 char ('RUM' or 'UMR'. This is a protection against bad translation)
-		return $pre.'-'.$row_code_client.'-'.$row_drum.'-'.date('U', $row_datec);
+		return $pre.($row_code_client ? '-'.$row_code_client : '').'-'.$row_drum.'-'.date('U', $row_datec);
 	}
 
 
@@ -1823,8 +1823,8 @@ class BonPrelevement extends CommonObject
 		$Rowing = sprintf("%010d", $row_idfac);
 
 		// Define value for RUM
-		// Example:  RUMCustomerCode-CustomerBankAccountId-01424448606	(note: Date is date of creation of CustomerBankAccountId)
-		$Rum = empty($row_rum) ? $this->buildRumNumber($row_code_client, $row_datec, $row_drum) : $row_rum;
+		// Example:  RUM-CustomerCode-CustomerBankAccountId-01424448606	(note: Date is the timestamp of the date of creation of CustomerBankAccountId)
+		$Rum = (empty($row_rum) ? $this->buildRumNumber($row_code_client, $row_datec, $row_drum) : $row_rum);
 
 		// Define date of RUM signature
 		$DtOfSgntr = dol_print_date($row_datec, '%Y-%m-%d');