Introduction
If you have a lost or damaged mobile device, or are otherwise unable to use your passkey or the Microsoft Authenticator mobile app, you can still sign in to services that require Microsoft multifactor authentication (MFA).
Cellular service is not necessary in order to use MFA. Multiple options are available.
Instructions
Passkey
If your passkey is stored in Apple Passwords, Google Password Manager, or another third-party password manager, you may still be able to use the passkey even without your mobile device.
EXAMPLE: If you are signed in to a Mac with iCloud, your passkey for Microsoft MFA may be synced to the Mac. In this way, even if you lost your iPhone, you can access the needed TTU services from the Mac and set up other MFA methods, if you like.
Security key
Use a WebAuthn/FIDO2 security key (for example, YubiKey).
Microsoft Authenticator mobile app
If the concern is having cellular service or a text messaging plan, please note that the Microsoft Authenticator mobile app can function via the Internet, both over cellular data and Wi-Fi, using the "number matching" feature (typing a two-digit code). Neither cellular service nor a text message plan is required.
If Internet service on your mobile device is not available via cellular or Wi-Fi, the Microsoft Authenticator app can still generate codes that can be used for MFA. Internet service is not required. This works using the industry standard RFC 6238 (TOTP) as an alternative method to number matching. You do not need to be connected to a network to use the app with the TOTP option. Please see how to use Microsoft MFA, step 4, section F for details on how to do this.
Text message or phone call
Although Microsoft has announced that they are removing the option to receive MFA codes through voice call or SMS text message, these options do exist through February 1, 2027. If you have them set up, there are ways to receive phone calls or text messages without a mobile device.
Carrier options that don't require a cellular signal
Some providers allow you to receive text messages and/or phone calls over the Internet without cellular coverage.
EXAMPLE:
- AT&T NumberSync
- T-Mobile DIGITS
- Verizon Messages (Messages+)
Please contact your provider for further details.
Alternatives to traditional postpaid cellular service
You can receive phone calls on a number that isn't a cellular number.
EXAMPLE:
If you expect to be in an area without cellular coverage and without Wi-Fi, you may wish to set up one of the options above as an option to have available as an alternative MFA method.
Another option is a prepaid cell phone ("burner phone").