Transaction Number - NSU

Indicates the sequence number (NSU – Unique Sequential Number) of the transaction assigned by the Host (System of the Card Networks that receive and process requests for TEF transactions). When this field is sent from the SiTef Client to the TEF requesting Terminal, it represents the Host NSU established for the transaction and when it is sent from the TEF requesting Terminal to the SiTef Client, it represents the NSU of the transaction to be handled (cancelled, confirmed, etc.). This field is numeric and has a size of up to 12 20 bytes.

In the TRNCENTRE sales transaction (ATTENTION: this field is informed in the response message of the Sitef, and therefore should not be informed by the POS, which may, at its discretion, capture this information or no)