What the Microsoft account security phone number does
The security phone number on a Microsoft account is used for identity verification, password resets, and account recovery.
If you no longer use that number, updating it helps keep access to services such as Outlook, OneDrive, Xbox, and Microsoft 365 reliable.
Knowing how to change Microsoft account security phone number matters because Microsoft may send one-time codes to that number during sign-in risk checks or recovery requests.
If the phone is outdated, unavailable, or linked to an old carrier, you can get locked out when you need access most.
Before you change the number
Before editing your security info, confirm that you can still sign in to the Microsoft account and that you have access to at least one existing verification method.
Microsoft may require a code, a trusted device, or another recovery option to confirm the change.
- Make sure the new phone number can receive SMS or voice calls.
- Use a personal number you can keep long term.
- Check whether the number is already tied to another Microsoft account.
- Have a backup method ready, such as an authenticator app or recovery email.
If you recently lost access to the old phone number, the process may involve Microsoft account recovery rather than a simple edit.
How to change Microsoft account security phone number
The standard method is through the Microsoft security settings page.
This is the most direct way to update the phone number used for verification and account recovery.
- Sign in to your Microsoft account at the official account security page.
- Open Security or Advanced security options.
- Find Security info or Ways to prove who you are.
- Choose Add a new way to sign in or verify.
- Select Phone and enter the new number.
- Choose whether to receive a text message or a phone call.
- Enter the verification code Microsoft sends to the new number.
- Set the new phone number as a security method.
- Remove the old number if you no longer need it.
Microsoft may label the steps slightly differently depending on whether you use a personal Microsoft account, Outlook.com, Xbox, or Microsoft 365.
The underlying process is the same: add the new number, verify it, then remove the outdated one.
What happens after you add the new number?
After the new number is verified, Microsoft can use it for sign-in confirmation, password reset prompts, and suspicious activity checks.
If you have multiple security methods, Microsoft may prioritize them based on your account settings and recent activity.
In many cases, the old number is not removed automatically.
Leaving outdated security info on the account can create confusion later, so it is best to review the full security info list and delete methods you no longer control.
How to remove the old Microsoft account security phone number
If the old number is still listed, remove it only after confirming the new number works.
This helps prevent a gap where neither number is available during a recovery request.
- Return to the Security info section.
- Locate the old phone number.
- Select Remove or the trash icon.
- Confirm the removal when prompted.
Some Microsoft accounts impose a waiting period before security changes take effect.
If Microsoft asks you to wait, follow the on-screen instructions and avoid making repeated changes, which can trigger extra verification steps.
Can you change the number without the old phone?
Yes, but it depends on whether you still have another way to verify the account.
If you can sign in with a password plus another method, you can often add a new phone number without using the old one.
If the old phone number was your only recovery method and you cannot receive codes anywhere else, use Microsoft account recovery.
Microsoft may ask for details such as prior passwords, subject lines from sent email, device information, or account activity to confirm ownership.
Common problems and fixes
The verification code never arrives
Check that the number is entered in the correct international format and that the phone has signal, SMS service, and no blocking rules for short codes or unknown senders.
If you selected a voice call, make sure calls from unknown numbers are not silenced.
Microsoft says the number is already in use
A phone number can sometimes be tied to another Microsoft account or used recently as a security method.
Try removing it from the other account first or choose a different number if available.
You are asked to wait before making changes
Microsoft may enforce a security cooling-off period after major account changes.
This is normal and designed to prevent unauthorized access.
Wait for the time period to expire, then try again.
You cannot sign in to reach security settings
Use the Microsoft sign-in helper and account recovery flow.
If you still have access to your email, authenticator app, or trusted device, use that method first because it is usually faster than a full recovery request.
Best practices for Microsoft account security info
Updating your phone number is a good time to review the rest of your security setup.
A stronger account typically uses multiple recovery methods rather than relying on a single phone number.
- Add a second verification method, such as Microsoft Authenticator.
- Keep your recovery email address current.
- Review trusted devices and recent sign-in activity.
- Use a strong, unique password for the Microsoft account.
- Enable alerts for unusual sign-in attempts when available.
For business users, organization-managed Microsoft 365 accounts may follow different policies.
In that case, your IT administrator or help desk may control security info updates, especially if the account uses Entra ID governance or conditional access.
When to update your number immediately
You should change the Microsoft account security phone number right away if the old number was reassigned, lost, disconnected, or shared with someone else.
Immediate updates are also wise after a carrier change, international move, or phone replacement that changes your long-term contact number.
If you suspect someone else may have access to your old number, review your account activity, change your password, and verify that all recovery methods point to information you control.
Related Microsoft account recovery terms to know
- Security info: The recovery and verification methods attached to your Microsoft account.
- Two-step verification: An extra sign-in layer that uses codes or approval prompts.
- Microsoft Authenticator: Microsoft’s app for approving sign-ins and generating verification codes.
- Account recovery form: Microsoft’s process for proving ownership when normal sign-in methods fail.
- Trusted device: A device Microsoft recognizes for easier verification.
Understanding these terms makes it easier to manage the account when phone numbers, devices, or recovery options change.