diff --git a/extend/application/controllers/fcPayOnePaymentView.php b/extend/application/controllers/fcPayOnePaymentView.php
index 72b847a..88dceb3 100755
--- a/extend/application/controllers/fcPayOnePaymentView.php
+++ b/extend/application/controllers/fcPayOnePaymentView.php
@@ -2732,9 +2732,9 @@ protected function _fcpoValidateBirthdayData($sPaymentId, $aRequestedValues)
             case 'fcpopl_secinstallment':
             case 'fcpopl_secdebitnote':
                 $blB2CMode = ! $this->fcpoIsB2BPov();
-                $blFieldPresence = isset($aRequestedValues['fcpopl_secinvoice_birthdate_day'])
-                    && isset($aRequestedValues['fcpopl_secinvoice_birthdate_month'])
-                    && isset($aRequestedValues['fcpopl_secinvoice_birthdate_year']);
+                $blFieldPresence = isset($aRequestedValues[$sPaymentId . '_birthdate_day'])
+                    && isset($aRequestedValues[$sPaymentId . '_birthdate_month'])
+                    && isset($aRequestedValues[$sPaymentId . '_birthdate_year']);
                 $blBirthdayRequired = ($blB2CMode || $sPaymentId == 'fcpopl_secinvoice') && $blFieldPresence;
                 $blValidBirthdateData = $this->_fcpoValidateSecInvoiceBirthdayData($sPaymentId, $aRequestedValues);
                 break;