First of all, you will need an account to be part of the Brown Bag Unlimited subscription. If you don't have an account, click here to create one. It's simple and takes less than a minute to do.
All you need to do is login to your account, add Brown Bag Unlimited to your bag (like you would any other product) and checkout as normal. From that point on, you will receive Free Next Day UK Delivery for a year, no matter how many times you order.