What it means
A linked WhatsApp Web, desktop or companion device can read and send messages on the account after it has been authorized. It appears in Linked devices on the primary phone. A second phone number registered as another account is a distinct identity and may not appear in that list.
A real-world example
A shared office computer remains linked after an employee leaves. Colleagues can access its session even though the employee still controls the phone number.
What to do
Review Linked devices on the primary phone, log out unknown or obsolete sessions, and protect the phone's unlock method. Warn contacts if messages were sent without you.
The distinction that matters
A device name or last-active hint helps triage but may be incomplete. Unlinking blocks future access through that session, not previously copied content. WhatsApp says it cannot give a complete forensic access history, so absence of evidence there is not proof no one read a chat.
WhatsApp device-audit limitations
