Account linking is a security process within Identity & Access Management (IAM) that establishes secure relationships between multiple user accounts belonging to the same individual across different systems, applications, or services. By creating a unified digital identity, it enables users to seamlessly access various resources without repetitive registrations or separate authentications, reducing login fatigue while enhancing administrative oversight of user permissions across an organization's digital infrastructure.

This process typically involves mapping unique identifiers between identity providers to enable federated authentication or single sign-on (SSO) capabilities. From a cybersecurity standpoint, effective account linking centralizes control over identity provisioning, deprovisioning, and privilege management, thereby reducing the attack surface associated with fragmented accounts. It ensures consistent enforcement of access policies, simplifies auditing of user activity, and contributes to stronger security posture, operational efficiency, and regulatory compliance.