Guest checkout is an online purchase flow in which a shopper completes an order without registering an account or signing in. The buyer types an email address, delivery details and payment details for that order only, and the merchant does not keep a password or profile. It is offered as an option at the start of the checkout on most e-commerce sites because forced registration is a well-known cause of cart abandonment, especially for first-time and mobile buyers.
The trade-off for the merchant is less customer data and no stored payment credential, so a repeat order cannot use card on file or one-click checkout. Many merchants narrow the gap by inviting the guest to save details after the order is placed, or by accepting a digital wallet that supplies the address and payment details in one step. Fraud teams treat guest orders with a little more caution because there is no account history to compare against.