Verifying a Microsoft account with a US phone number

Microsoft’s phone rules at a glance

From Microsoft Support and the Microsoft Services Agreement, read on 13 November 2026. Microsoft doesn’t document the code’s length.

What Microsoft says about the number you add

Microsoft’s troubleshooting page puts it in one line: “VOIP numbers cannot be added as a way to sign in or get verification codes.” It asks for a mobile number instead. Microsoft also says a phone number can be added to a single Microsoft account only, and that on some accounts the option to add a new number may not be offered at all.

Microsoft explains that carriers can reuse a number after 30 days, so a number new to you may still be on its previous owner’s account. If so, it suggests trying again after 30 days to see a Transfer option; if the number was only recently added to that other account, its advice is to use a different mobile number. The Services Agreement asks for accurate sign-up information and forbids creating fake accounts.

A number from us is a non-VoIP US number, which is the kind that rule leaves open. Microsoft still decides whether to send a code; if none arrives, cancel within 24 hours.

Receiving Microsoft’s code on a number from us

1. Get a number for a week

   A week gives you room to verify and then move the account onto email and a passkey.

2. Add it where Microsoft asks

   Either the product that wants a number asks for it, or you add it yourself at account.microsoft.com/security: choose Manage how I sign in, then Add a new way to sign in or verify. Pick United States, enter the number and ask for a text.

3. Copy the code into Microsoft

   The text shows on the number’s page with the code picked out. Copy it and type it on Microsoft’s screen.

How long to keep the number

A week ($7.99) if you move the account off the number once you’re verified, which is the direction Microsoft itself is taking. It says SMS-based authentication “is now a leading source of fraud” and names passkeys and a verified email as the replacements. In that week:

1. At account.microsoft.com/security, add a verified email and a passkey, or the Authenticator app.
2. Remove the number from your security info. If the number is also a sign-in name, remove it at account.live.com/names/manage. Microsoft only allows that when the account has another username, so add your email as one first.

A year ($34.99) if the number stays on the account as security info or a sign-in name. Once a rental ends the number can go to someone else, who would receive Microsoft’s codes for it. And if you lose every way to verify, replacing your security info starts a 30-day wait before you can sign in with the new details.

If Microsoft’s code doesn’t arrive

• Check which number it went to. Microsoft shows only the last two digits of the number on file; make sure they match.
• Stop requesting. Microsoft warns that repeated requests can bring temporary or permanent blocks, and that more attempts can reset a time lock. It says waiting a day is sometimes enough to lift a block.
• Try another method. Microsoft suggests a different verification method on your account, and notes that its SMS service has limited functionality in some regions.
• “This phone number has already been taken.” The number is on another Microsoft account, and only one is allowed.

If no text has reached the number, cancel it from its page within 24 hours of buying. The general checklist is in verification code not received.

Questions people ask

Why can’t I add my new phone number to my Microsoft account?

Microsoft gives three reasons: VoIP numbers can’t be added, a number can be on only one Microsoft account, and some accounts aren’t offered the option to add a number. If the number recently belonged to someone else, Microsoft suggests trying again after 30 days to see a Transfer option.

Is Microsoft stopping text message codes?

For personal accounts, yes. Microsoft says it will start phasing out SMS for sign-in and account recovery, gives no date, and points to passkeys and a verified email instead.

How do I change the phone number on my Microsoft account?

Add the new way to verify at account.microsoft.com/security under Manage how I sign in, then remove the old number. If the old number is also a sign-in name, remove it at account.live.com/names/manage, which needs another username on the account.

Can I move my phone number to a different Microsoft account?

If both accounts are yours, remove the number from the old account first and then add it to the new one. Because a number can be on only one Microsoft account, it can’t sit on both.

What happens if I lose access to all my security info?

At Verify your identity, choose I don’t have any of these and replace it. You then wait 30 days before you can sign in with the new info, and Microsoft says its support agents can’t send reset links or change account details for you.