EDI Trading is a mandatory requirement when joining NMBS as a supplier. Electronic Data Interchange (EDI) is the electronic exchange of business documents in a standard electronic format between business partners. EDI replaces Paper and Emailed PDF documents which must be handled by people rather than computers, which slows the processes down and introduces the potential for errors. EDI documents, in comparison can flow straight through to NMBS’s back office and processing can begin immediately. EDI documents are generally posted to NMBS ledgers within 24 hours of receipt (except at weekends) and passed on to members the next working day.