If you have set up 2FA to receive login codes via SMS on your mobile device, you will need to enter these every time you log in to your wallet.
How it works
First, link and verify your mobile number. This article walks you through the steps on how to do that. You can then proceed to Level 2 of the Security Center of your wallet, at which point you can enable two-factor authentication (2FA).
Once you have enabled 2FA (learn why we strongly recommend enabling this feature), all subsequent logins will require you to input your wallet ID, password, and then a 2FA code that you should receive via text message or SMS on your mobile phone.
What if I’m not receiving any SMS messages?
First, give it a few minutes. Occasionally, SMS messages can be delayed by as much as 5 minutes. If after 5 minutes you still have not received your login code via SMS, check your service and contact your service provider to verify that there are no issues on their end. SMS message delivery failure may be caused by provider blockage, poor signal, regional restrictions or a variety of other reasons.
If you have checked with your service provider and verified that there are no known service issues that could be impacting your SMS deliveries, please contact our support team so that we can investigate the issue and help you regain access to your wallet. You can also go ahead and submit a request to reset 2FA for your wallet to access your wallet with just your identifier and password. Please note that this process includes a mandatory waiting period for security reasons.
If you require urgent access to your funds and are not receiving your SMS codes, you can always use your 12-word recovery phrase to restore your funds in a new wallet, here: https://blockchain.info/wallet/#/recover. Please note that imported addresses are not backed up by the recovery phrase and will not be restored.
SMS as a 2FA method
We recommend Google Authenticator over SMS if you have a smartphone. Google Authenticator is not only free, the app generates a new login code every 30 seconds locally on your device. The delivery of SMS codes, on the other hand, is entirely dependent upon the reliability of your mobile provider. During a service outage, delivery may be delayed or disabled completely. This means you may not be able to receive the codes needed to log in. There are other risks with SMS as well, including social engineering tactics used to port your number. If successful, an attacker can receive your SMS codes (and any other incoming SMS messages). You can download the Google Authenticator app from the App Store for iOS or the Play Store for Android. If you prefer physical keys, we also support and recommend Yubikey, which you can get from Yubico.