If you have a promotional discount code for a book, you will be able to input the code in the appropriate box on the way to the checkout.
If the code offers free post and packing, an amount for postage will still appear on the invoice but the final amount will represent the correct offer.
If you have more than one discount code, you will need to put through the orders for each book separately. This will not cost you any additional postage. We apologise for any inconvenience.