In other systems I have used you are able to set a default nominal code for each supplier to save time having to type in the nominal code every time.
For instance EDF is our electricity supplier so it would be good if when ever we entered an invoice from EDF the system pre-filled the nominal code for us with electricity.
This could be done simple by adding a 'Default Nominal' user/analysis field to the PURCHASE ledger and amending the UDIs for invoices and credit notes to pick it up. 1 - 2 hours consultancy work.