Automatic OTP verification in iOS?

In iOS 12 Apple has introduced feature called Security Code AutoFill.

To use this in your app all you need to do is set UITextField's input view’s textContentType property oneTimeCode.

otpTextField.textContentType = .oneTimeCode

NOTE: Security Code AutoFill will only works with System Keyboard it will not work with custom keyboard.

WWDC video

When you get OTP it will look something like this:

It is also important that the text message you receive contains something with "code" like

"your passcode is:123456"

or

"12345 is your code to log in"

something along that line.

NOT!

Your App: 12345

you can verify if the code in your text message will work with the .oneTimeCode type by tapping the underlined code in your message. If a dialog pops up that says "copy code", you are good to go. Otherwise you might need to change the text of your message.

UPDATE

From iOS 12 Apple will supports Password AutoFill on UITextField, UITextView, and any custom view that adopts the UITextInput protocol. System keyboard set the textContentType on it to .oneTimeCode

1) Using Code

singleFactorCodeTextField.textContentType = .oneTimeCode

2) Using Storyboard/XIB

Select UITextField/UITextView in storyboard/XIB click Click on Attribute inspector. Go to text input trait, click to Content type and select one time code and done.

The operating system will detect verification codes from Messages automatically with this UITextContentType set.

Warning

If you use a custom input view for a security code input text field, iOS cannot display the necessary AutoFill UI.

For more information, you can check it on the Apple developer oneTimeCode

And also review WWDC 2018 Session 204 - Automatic Strong Passwords and Security Code AutoFill and jump to 24:28 for automatic pre-fill the OTP.