Fees are usually cash payments that are not directly related to delivery of a commodity
There are four general categories of fees:
Broker and clearing fees - fees associated with the execution of each trade - these can normally be booked directly against each trade as the ay are incurred
Trade services fees - fees generally associated with the delivery of physically shipped commodities like coal and oil - again normally booked against individual trades as they are incurred
Non-trade specific fees - cash costs which are incurred as a result of trading - but cannot be allocated to specific trades - for example imbalance costs
Non-trade fees - cash costs associated with licences, membership costs etc.
Fees booked against trades are generally associated with a cash flow type, so that they can be correctly allocated in P&L, invoicing and general ledger accounting