If you've got a passcode set on your iPhone, Siri and Passbook will still work by default on your Lock screen. This means that anyone who wants to talk to Siri or use one of your passes will still be able to. While it's convenient, it can be a bit unsafe. If you prefer having to use your passcode in order to use them, you can easily do so through the Settings app.
How to disable Siri and Passbook access on your iPhone or iPad's Lock screen
- Launch the Settings app on your iPhone or iPad.
- Tap on Touch ID & Passcode.
- Enter your passcode when prompted in order to continue.
- Under the Allow Access When Locked section, turn Off the options for Siri and Passbook.
You can of course choose to only disable one or the other if you want. For instance, if you want to be able to use Siri from the Lock screen but just want Passbook to be more secure, just turn Off the option for Passbook and leave the option for Siri turned On. Whatever combination you want to use, you can.
Note: Originally published, March 2013. Last updated, October 2014.