Hi nellymc
Currently AccountRight doesn’t have the capability to automatically calculate and add additional percentages to the sale.
If you were using Item invoices however, you could create an inventory item to calculate it for you. The item would need to have I sell this item ticked to be selectable on the invoice, but not I inventory this item.
In terms of the item price it would be the percentage you were wanting to calculate, so a 10% calculation would be an item price of $0.10 or 10 cents
When using the item, enter in all the other transaction lines to get the total of the invoice before the levy, then add the levy as an item for sale. Using the pre levy total of the invoice as the quantity for the levy will let it calculate and add the amount to the invoice