XSD Files - Sistrategia/SistrategiaCFDi GitHub Wiki XSD Files by version cfdv1.xsd cfdv2.xsd cfdv22.xsd cfdv3.xsd cfdv32.xsd cfdv33.xsd Anexo 20 and XSD Files (Last and updated version): http://www.sat.gob.mx/informacion_fiscal/factura_electronica/Paginas/Anexo_20_version3.3.aspx Reference: http://www.sat.gob.mx/informacion_fiscal/factura_electronica/Paginas/validacion_comprobantes.aspx