FAQs
If delivery of your two-step authentication code to your phone is taking a significantly long time, try restarting your phone to refresh network connectivity. If you are not receiving the SMS code at all, see Not receiving text message (SMS) verification code for two-step authentication verification.
What's wrong with SMS 2FA? ›
SMS has long been regarded as a vulnerable communications protocol by security experts—but where 2FA is concerned, the biggest danger is with the possibility of SIM-swapping attacks. In a SIM swap, the bad guys trick cellular carriers into transfering a phone number to a SIM card that they control.
Why is my 2FA authenticator not working? ›
Authenticator apps rely on the time set on your device to create the authentication code. If the time on your device does not match the time on your computer then the code will not work. Check the time and date on your phone and make sure they match the computer or device you are logging in from.
Why not to use text for 2FA? ›
First, let's talk about why SMS 2FA is the weakest form of multi-form authentication. It is dependent on the device. The One Time Password sent via text has larger validity than the codes in the authenticator apps. Hence, giving an attacker enough time to conduct the attack.
Why am I not receiving text verification codes? ›
Causes of Not Receiving Verification Code Texts on Android
You provided the wrong phone number. Your inbox is full. Your phone is set to block messages from unknown senders. Your phone carrier is blocking the message.
Why is my verification SMS not coming? ›
Your mobile device might be out of network coverage. Make sure there's enough signal to receive a text message. Your phone might have been powered off when the text message came. You might need to check whether you prefixed your phone number with a correct country code.
Why is my two factor authentication failing? ›
Problems logging into your account
The most common cause of 2-factor authentication problems is that the time on your Google Authenticator app is not synced correctly.
How do I enable 2FA via SMS? ›
Two Factor Authentication using SMS Authentication
Choose SMS Authentication and enter your mobile phone number. Click Confirm Number to verify your phone number. Check your mobile phone for the SMS verification code and enter it in the designated field. Then, click Confirm Code.
Why do I keep getting an incorrect 2FA verification code? ›
The most common cause for Incorrect Code errors is that the time on your device is not synced correctly. To make sure that you have the correct time in your Google Authenticator app, follow the instructions for your operating system below.
Why am I not getting a notification for 2-Step Verification? ›
If you're not getting the app notification for 2-step verification, check that: wifi or mobile/cellular data is turned on. you're checking the app on a device you set as trusted. you don't have power saver mode on.
Check if the Microsoft Authenticator app is up to date. You can update the app from the app store on your mobile device. In your iOS/Android device settings please make sure that battery optimization is turned off for Microsoft Authenticator App and it is allowed to run in background.
Why is my authentication failing? ›
Authentication failure occurs when the request to a resource is missing or has invalid credentials.
What is the problem with SMS authentication? ›
The main risks include: Interception of SMS messages: SMS messages are unencrypted and can be intercepted by attackers. Mobile network dependency: Outages can prevent receiving authentication codes. SS7 vulnerabilities: Though less common now, attackers can exploit the SS7 protocol to intercept messages.
Which is better SMS or authenticator app for 2FA? ›
An authenticator app is safer than SMS authentication because it generates 2FA codes locally, which prevents cybercriminals from intercepting the codes as they can with SMS.
What are the disadvantages of SMS 2FA? ›
While SMS-based MFA is a popular method, it also comes with several risks and limitations. One of the primary dangers of using SMS for MFA is the potential for interception. SMS messages are not encrypted, and attackers can intercept them using various techniques, including phishing, malware, and SIM-swapping attacks.
Why am I not getting a notification for 2-step verification? ›
If you're not getting the app notification for 2-step verification, check that: wifi or mobile/cellular data is turned on. you're checking the app on a device you set as trusted. you don't have power saver mode on.
How do I unblock an SMS verification code? ›
Steps to Unblock SMS Verification Code
Contact Your Carrier: Reach out to your mobile carrier to see if there are any restrictions in place that could be blocking SMS messages. Update Phone Settings: Check your phone's settings to ensure that messages from unknown numbers are not being blocked.
Why am I not getting my two-step verification code on my iPhone? ›
Trusted phone numbers don't automatically receive verification codes. If you can't access any trusted devices when setting up a new device for two-factor authentication, tap “Didn't get a verification code?” on the new device, then choose one of your trusted phone numbers to receive the verification code.
Why is my Samsung account not getting two-step verification SMS? ›
There are multiple reasons why a verification code isn't received: The code was sent to the wrong number. The Send code button wasn't clicked. Weak network connection.