I was recently working with an iPhone user who noticed that since updating to iOS 14, they were being prompted to set up two-factor authentication on their Apple ID. They temporarily dismissed the prompt by navigating to Settings, tapping the "Two-Factor Authentication" option and selecting "Not Now" – but out of interest, will this prompt re-appear – or does choosing this option disable all future prompts from appearing on that device (or Apple ID)?
IOS – Does disabling the prompt to enable two-factor authentication on an iOS device disable future prompts from appearing
apple-idiosSecuritysettingstwo-factor-authentication
Related Solutions
Two-Factor Authentication is applied at the account level, not at the device level. So you can either remove it entirely from your iCloud account, or you’ll have to use it on all of your devices equally.
If it worked any other way a hacker could simply pick the least secure entry point to attack your account.
Thankfully you can still login on an older device, even with Two-Factor Authentication enabled.
First, login using your regular credentials, just as you would on a system that did support Two-Factor Authentication. An authentication code will be sent to all your Trusted Devices. Now simply login again, this time appending your authentication code to your password.
For instance if your account is basil@icloud.com, your password 123apple and your authentication code 456789, then you would login using the following credentials:
basil@icloud.com
123apple456789
You can read up more about this at Two-factor authentication for Apple ID:
What if I use two-factor authentication on a device running older software?
If you use two-factor authentication with devices running older OS versions, you might be asked to add your six-digit verification code to the end of your password when signing in. Get your verification code from a trusted device running iOS 9 and later or OS X El Capitan and later, or have it sent to your trusted phone number. Then type your password followed by the six-digit verification code directly into the password field.
Apple also provides a few additional methods to Get a verification code and sign in with two-factor authentication.
Even if you don't want to set up 2FA, choose the Continue button from the top of the iCloud pane, then you can choose the "not now" option and the warning will disappear.
Best Answer
You cannot guarantee that the user will not be prompted in the future.
There's a continued development in security and the need for preventive measures. Today two-factor authentication is absolutely crucial and wide-spread, 25 years ago it was only used by the few.
Apple some times "moves the bar" by changing the minimum security requirements. In those cases, they could start prompting user's again for enabling two-factor authentication - or even requiring it entirely.
For example, not so long ago the requirements for developer accounts were changed so that these users must have two-factor authentication enabled (also affects apps such as TestFlight, App Store Connect, etc.). These users were notified in advance that this requirement would be instated.