Answer is revealed here.

By signing up to an account and logging in each time you visit our Shop, you’ll benefit from a saved list of your chosen delivery addresses and easy access to your order history and current order status.

If you’re eligible to purchase items without VAT as a blind or a partially sighted person, this status will also be remembered and VAT automatically deducted in your basket on eligible items.

All products on the shop have their excluding VAT and including VAT prices displayed, apart from publications which have a single zero-VAT price.

You will see one price displayed when browsing categories and in search results. This is the ex VAT or zero-VAT price.

You will see two prices displayed when viewing the product details. These are the ex VAT and inc VAT prices.