The payment processing part of our Express Checkout is controlled by PayPal and they may choose to deny the process of a payment if it is over a certain value. This value is undisclosed by PayPal but is within the £1,000 region. This decision is based on several risk factors, including but not limited to the buyer's PayPal purchase history, PayPal cookies stored on the buyer's computer, the buyer's location, or a credit assessment.