Security Code Autofill

Over the last year or so Apple has really pushed its users to sign up for Two-Factor Authentication (2FA) on our iOS and Mac devices. Two-Factor Authentication is much more secure than any previous sign-on methods to date. However, it is a real hassle to use, requiring a 6 digit Security Code to complete the authentication. In an effort to ease the pain Apple has provided the Security Code Autofill feature in iOS 12 and macOS Mojave.

Security Code Autofill

Here is why have people have been reticent to use the new Two-Factor Authentication from Apple. When you sign up for Two-Factor Authentication on a service, you have to enter a 6 digit Security Code to complete your login. Apple has created the Security Code Autofill feature to complete the sign in. How does that work? Here is a fairly clear explanation:

Security Code Autofill automates the process of taking the security code from the text message and entering it into the part of the app or service you’re trying to log into. Synchronizing text messages through iCloud allows the operating systems to take 2FA passcodes from the iPhone and use them in Security Code Autofill in Safari on the Mac.

I will use a sign on to my Backblaze backup service account as an example. Backblaze does not require Two-Factor Authentication, but if you are storing all your files and folders online. it is not a bad idea to make it as secure as possible.

This is the login screen for my Backblaze account:

Backblaze email

You enter your email and click Next:


Then, you enter your password and click “Sign In”. Once you do that you are asked to enter a 6 digit verification code which is sent to your iPhone:

Verification Code

You can go onto your iPhone Messages App and get this code manually, but that is what people object to doing. It is just too much of a pain to remember a 6 digit code from your device to your Mac. However, if you wait for a couple of seconds the Security Code Autofill feature will pop up the code from the iOS Messages App on your Mac screen. Just click on that little popup and the code is entered into the verification field:

Messages Code

Then all you have to do is click on “Enter Code” and you are logged into the account in question using Two-Factor Authentication. Somehow the Security Code Autofill feature does all this through iCloud. I don’t know exactly how it works this out, but I like it!

Here is an article from Apple on how to setup Two-Factor Authentication on your Apple ID. Third party Vendors like Backblaze allow you to use that Two-Factor Authentication on their websites. But, it all goes through your Apple ID in the Messages App on your iPhone.


I think Two-Factor Authentication makes sense in certain places, especially if money is involved. I have it setup on several services. Thankfully, the Security Code Autofill feature makes it relatively easy to use.