Using Ordnance Survey voucher is very easy. You can add a voucher by following these steps. 1. Select your product and add it to your shopping cart 2. In the shopping cart, you can check the items ordered and then click "CONTINUE CHECKOUT". 3. If you already have an account you must log in, if you do not have a website account you must register with your email address and choose a password 4. Fill in the name and address of the delivery and then fill in Ordnance Survey voucher code on the order summary page 5. Click the Apply button to activate the voucher code 6. Once the discounted price is displayed, proceed to the next step to complete your purchase.