File transfer services are commonly used to offer regular (e.g. weekly, monthly, annual) bulk data files that include all records that have been added, changed or deleted in the national bibliography. In the past such files have traditionally been offered in the MARC format (or formats) supported by the NBA. However more recently data has begun to be made available in newer XML based formats including: MARCXML and MODS, together with PDF for electronic versions of the printed national bibliography. 

Regular MARC files offer a convenient option for customers wishing to load metadata from the national bibliography into their local integrated library systems due to the fact that most ILS providers currently offer a MARC load interface as a standard feature.