Guest checkout is a popular feature in e-commerce as it simplifies the purchasing process by allowing customers to complete transactions without creating an account, thereby increasing conversion rates. However, this convenience can also facilitate fraud, as it lacks persistent identifiers that help track suspicious activity, making it harder to detect and prevent fraudulent behavior such as stolen credit card use or chargeback fraud. Fraudsters exploit this anonymity by using tactics like VPNs and browser tampering to mask their identities. To combat this, the article highlights the use of device intelligence, specifically Fingerprint's technology, which assigns a unique visitor ID to recognize devices even if cookies are cleared or IP addresses change. This tool provides insights into potentially risky behavior, allowing merchants to flag and block fraudulent transactions without disrupting the guest checkout experience for legitimate customers. By integrating such device intelligence, businesses can maintain the benefits of guest checkout while effectively preventing repeat fraudsters from exploiting the system.