The transaction can also be a receipt (e.g. a milk collecting truck). A transaction is settled when the parties interested in the transaction have made their agreement known (explicitly or implicitly) as regards the amount of the transaction. This may be a payment, signing a credit card voucher, signing a delivery order, etc. The parties interested in a transaction may be the parties themselves or their representatives (for example: the employee in a filling station, the driver of a tanker).