Quick answer
If you've lost your phone and can't complete two-factor authentication, first use backup codes or another signed-in device. Then check account recovery options (backup email, phone, authenticator app). If nothing works, contact the service's support and report the device as lost.
How to recognize the problem
- You can't sign in because you don't have access to the authenticator app or SMS code
- The phone is lost, stolen, or broken, and 2FA is tied to it
- You don't have saved backup codes for account recovery
- Signing in to the account requires confirmation via a phone you no longer use
Most common causes
2FA is tied to only one device
If you enabled two-factor authentication only via SMS or an app on your phone, losing the phone means losing the second factor.
You didn't save backup codes
Backup codes are one-time passwords that let you access your account when you don't have your phone. If you didn't save them, recovery is harder.
No backup sign-in method
Many services offer recovery via a backup email or phone number, but only if you set them up in advance.
The phone is stolen or lost
In that case, not only do you lack 2FA access, but there's also a risk that someone unauthorized could access your accounts.
Step-by-step fix
- 1
Try signing in from another device
If you're already signed in on another device (computer, tablet), use it to change settings or add a new sign-in method. For example, in your Google account go to
Securityand remove the old phone or add a new sign-in method. The same applies to a Microsoft account, where on the account security page (account.microsoft.com) you can update verification methods. - 2
Use backup codes
If you saved them, each backup code can be used only once. When signing in and prompted for a 2FA code, select
Use backup codeand enter one of the saved codes. If you don't have codes, move to the next step. - 3
Check account recovery options
On the sign-in page, select
Can't sign inorDon't have access to your phone. The service will offer alternative methods, such as sending a code to a backup email or phone number. If you set those up in advance, you'll be able to regain access. - 4
Contact the service's support
If no automatic method works, contact the service's customer support if available, or follow the official account recovery procedure. Explain that you lost your phone and can't complete two-factor authentication. Sometimes they'll ask for additional proof of account ownership.
- 5
Report the phone as lost and block the SIM card
Immediately call your carrier and block the SIM card to prevent misuse of SMS codes. If the phone was stolen, report the theft to the police. On Android or iPhone, you can remotely erase data if you previously enabled device finding (Find My Device on Android or Find My on iPhone). Before remote erasing, check that you have a backup, because data is permanently removed.
- 6
Change passwords on all important accounts
Once you regain access, immediately change passwords on email, social media, and banking apps. Use strong and unique passwords, preferably with a password manager. Enable 2FA on all accounts where available.
- 7
Set up new 2FA methods
Instead of SMS, use an authenticator app (e.g., Google Authenticator, Microsoft Authenticator) or a hardware key. Save backup codes in a safe place, separate from your phone. Also consider syncing 2FA codes between devices if the service supports it.
If nothing helps: advanced options and business accounts
If the account is a business one (Microsoft 365 or Google Workspace), your company's administrator can reset 2FA or grant you temporary access. For personal accounts, some services offer recovery via identity verification (e.g., sending a scanned ID), but that's a slow process and not always available. If the phone was stolen, be sure to notify your bank and carrier. For the future, consider using authenticator apps that back up codes to the cloud (e.g., Authy, Microsoft Authenticator) or hardware keys (e.g., YubiKey) as an additional factor.
How to prevent it
- Save backup codes in a safe place, separate from your phone (printed or in a password manager).
- Set up multiple 2FA methods (e.g., authenticator app and hardware key, where available) and regularly update recovery information.
- Enable remote erase and device finding (Find My Device / Find My iPhone).
- Use authenticator apps that support backups or synchronization.
When to call a professional
If you have a business account or can't regain access even after all steps, contact IT support. They can reset 2FA or help you regain access safely with less risk of permanent data loss.
IT infrastructure maintenance · Servers, networks, backup, security and helpdeskFAQ
Can I regain access if I don't have backup codes?
Yes, but the process depends on the service. Most offer recovery via a backup email or phone number, if you entered them in advance. If not, contact the service's support and follow their instructions.
Is it safe to use SMS as 2FA?
SMS is better than nothing, but it's vulnerable to SIM swapping and interception. An authenticator app or hardware key is recommended, as they are more resistant to attacks.
What should I do if my phone is stolen?
Immediately block the SIM card with your carrier, report the theft to the police, and, if you have a backup or are prepared to lose data, remotely erase the device. Then change passwords on all accounts and notify your bank if you use mobile banking.