Example for the UK

The Example for the UK demonstrates how to use the BACS / SEPA converter maps.

Note: This format is available for purchase from APACS at www.apacs.org.uk, and references Standard 18 - 1 October 2002.pdf BACS Interchange Standards (v18/9 dated 1 October 2002)

The BACS standard contains two formats for data records: BACS input and BACS output. Both of these formats have the same basic field structure of 100 bytes, but the BACS output format is extended by additional fields. The BACS standard also defines Volume and File and User Header records which vary in size. The BACS input and output formats are described in as follows:

BACS input - This format is used by Banks, and their customers, to send payment data to BACS by electronic transfer, or other means. After initial validation, the data is forwarded to the relevant bank(s) using BACS output format. The BACS input format can be either 100 or 106 bytes. The additional 6 bytes are used to specify individual processing dates within BACS. For full details on this process, refer to the BACS User Manual.
BACS output - The BACS output is always 120 bytes. The additional 20 bytes contain fields added after validation by BACS: Error Code, BACS User Number and BACS Reference (unique reference for each payment; used by BACS for query purposes).

The SEPA type tree and converter maps are based upon the output format. If conversion to and from the input format is required, it can be easily achieved since the base 100-byte format is identical, although the extra data provided by the BACS output format is useful in providing additional unique identifiers for each transaction.

There are several types of data records in BACS format. These data records are identified by Transaction Code (TX Code) and vary depending upon whether the sender is a Bank or a Bank’s Customer. The SEPA type tree contains a single file description containing all possible record types.