My current invoicing system can only process products in euros. We will have shortly customers from the UK, they will be charged in pounds. We will offer to the British customers our products in our country which has products in euros, so we will need to adapt the resulting invoice according to the EURO-POUND exchange rate. Our customers are paying by direct debit.
How are you doing the conversion? Maybe using any outsourcing API service for salesforce? We want to do the conversion right before generating the invoice.