This occurs when a user checks out as a guest or using PayPal express, which creates a guest checkout instance in our system that is unable to link to a previously made account.
If you checked out as a guest you can still contact the Seller, if needed, from your Order Summary Page. Locate your order confirmation email and here you'll find a link to your personal order summary page.
From here you'll be able to contact the seller and view updates on your order, including dispatch and delivery updates. You can find more information on Guest Checkout here
If you didn't find what you were looking for here, you may wish to visit our FAQ's where you can find lots of helpful articles.