Lately many iPhone users have been complaining of the autofill error in iOS8 and iPad mini as well as some other apple phone and tab models.
As it is known the problem persists for some websites on safari. This could be a result of the latest update you did. While the solution for safari may work if you follow a short procedure to turn on settings that got turned off at some point – go to Settings > Safari > Passwords & Autofill > Names & Passwords ‘On’ or if private browsing is activated in safari, try turning that off.
on the other hand for the iOS related autofill issues we can try a couple of methods. If you have multiple usernames or domains saved in Keychain for example “Joe” and “joe” or beforeyoubuyit.com and www.beforeyoubuyit.com. The solution is to go into Settings on each iOS device and delete the saved user/passwords. Settings > Safari > Passwords & Autofill > Saved Passwords > Click Edit, then check the user/password pair(s), then click Delete.
Do recheck if the login details are not repopulated in the saved password list. Then go back to the problem website and log in with your username & password, saying yes to the Keychain prompt. Then logout and login. when you hover over the “Username” field the keyboard should show up, with “Autofill password” just over the QW keys. If that doesn’t work on an iPad, try the same thing on your iPhone, then go back to the iPad. that is one solution. Other useful solutions can be found at https://support.apple.com/en-lk/HT203783
WHAT ABOUT WEBSITES WHICH DO NOT PROMPT TO SAVE USER INFO?
for iOS7 try Settings -> Safari -> Passwords & Autofill -> Always Allow