How to set up the Battle.net Authenticator and save your restore code

Blizzard’s articles use two names for one thing: the same setup step says Battle.net Phone Notifications in one article and SMS Protect in another. Both mean a verified mobile number on your account, and the authenticator will not attach without it.

When you cannot log in, a text to that number can unlock the account, remove a lost authenticator, recover your account name or approve a password reset. It also alerts you to password changes, security feature changes and logins that lock the account.

The number belongs to you, not the handset, so a replacement phone with the same number keeps working. If you change numbers, update it first on Account Details, verifying with an authenticator, SMS or email code. Support staff cannot add a number for you.

Older videos show a standalone Battle.net Authenticator app. Blizzard moved it into the Battle.net Mobile App with a migration deadline of January 5, 2024, and said it would then remove authenticators from accounts that had not moved, reset their passwords and notify them. If yours vanished in early 2024, that is why.

Physical keychain authenticators are legacy too. Blizzard says a fob giving invalid codes may have a dead battery that knocked its timing out of sync, and points owners to the mobile app. Remove the physical one before attaching the mobile one.

One setup trap: if a serial number gets “Invalid Serial Number”, Blizzard’s first fix is to leave out the dashes.

Blizzard’s help pages only describe its own authenticator inside the Battle.net Mobile App. None of them list Google Authenticator, Authy or another app for Battle.net, and Blizzard does not support the same serial number on more than one device. Tricks that copy the secret into another app are outside anything Blizzard documents.

Call of Duty players can mix the two up. The Activision account behind Call of Duty has its own 2FA that does use third-party apps, and Blizzard Support says it cannot help with Activision accounts.

Battle.net also supports passkeys, which replace the password at sign-in and live on your phone or PC. Open the Security section of your account, select +Create a passkey and follow the prompts on the device that will hold it. Blizzard frames it as an addition to the authenticator, not a replacement. Lose the passkey device and you can still sign in with your password or an emailed one-time code, then remove it.

With the serial number and restore code in hand, it takes a minute. Install the Battle.net Mobile App on the new phone, open Authenticator, choose Restore my Authenticator and enter both codes. Each authenticator is tied to one device and Blizzard does not support the same serial on two phones, so a restore is a move, not a copy.

Never saved the codes but still have the old phone? Copy them from its cogwheel menu first. Or detach the authenticator on the website and attach a fresh one on the new phone.

If the old phone is already gone, the fix depends on whether your number still works. Our lost-phone guide covers it in order.

Sign in to the Account Security page at account.battle.net, click Update, then Detach Authenticator and Detach. Pass the security check with a text to your phone or a code from the authenticator, submit, and the serial number is unlinked.

Disabling the authenticator inside the mobile app is not the same. Blizzard notes that it does not detach the authenticator from your account; detaching only happens in your account settings on the website.

Locked out? Start with Can’t Log In on the login screen. With SMS on the account, a text verification removes the old authenticator; without it, Blizzard says to try account recovery, then contact support.

Blizzard has a short fix for most authenticator errors.

A screenshot of your restore code only helps until you lose the phone holding it. Blizzard’s security checklist says a password manager can help generate and store stronger passwords, and a LoginScout card keeps the login and these notes together, encrypted on your device.