Issues with Multiple Microsoft Accounts Using the Same Phone Number

hi martinhocking​ It sounds like it is getting confused because the same phone number is tied to multiple accounts — it’s treated as a unique security ID. A good workaround is to use Microsoft Authenticator for sign-ins instead of SMS, and assign different recovery options (like alternate emails) to each account. Also, be sure to sign out of all sessions before verifying ownership. If the issue continues, Microsoft Account Support can help separate your verification methods safely.