Hi raymondo
We presume that you do not want the invoice to the client to show the commission. In this case you will have to create the invoice with one line showing the amount and 20%S tax, you will have to save it, the opaque save, print/send this to your client. You will then have to add a second line, creating a service for the commission, in the income account for the service you will have create/select a commission expense account and on the invoice enter the amount in a negative figure and select No VAT, select save, print/send to your broker.
