Spec for credit transfer: 
https://docs.oracle.com/cd/E39124_01/doc.91/e60210/fields_sepa_pay_file_appx.htm#EOAEL00515

To validate a SEPA file:
xmllint --schema pain.001.001.03.xsd T200801.xml --noout

To test a SEPA file: 
https://www.mesfluxdepaiement.fr/testez-vos-fichiers-sepa 
