iPhone Xs, iPhone Xs Max and iPhone XR include a new feature for NFC that Apple didn’t mention on stage. The new models will be able to scan NFC tags in the background. With current iPhones, users must first launch an app to enable NFC Reader mode.
iPhone Xs and iPhone XR require no such preamble, the user can simply walk up to a compatible NFC tag, wake the iPhone screen, and scan it …
If detected, the NFC scan will trigger a notification to appear on the lock screen of the iPhone Xs or iPhone XR. The user can then tap the alert and launch the app into the foreground, passed the context of the NFC tags.
There are some constraints to this system. Any NDEF tag is supported that ends with a URL that is registered with Apple’s Universal Link system. Background tag reading happens whilst the iPhone display is on (either on lock screen or home screen).
Background tag reading requires the device to have been unlocked at least once since it has been rebooted. It also is disabled if Apple Pay Wallet session is active, if Airplane mode is enabled, or if the camera is on.
In addition to custom URL schemes to support third-party specific app tags, iOS will integrate with several default URL scheme types to offer intuitive behaviour. If a NFC tag is encoded with a URL, the user will be able to scan, tap the notification, and launch Safari. Similarly, an email tag can launch Mail and a phone-number-encoded tag can start a phone call.
Note that in every case, explicit user action is required to initiate the action by tapping on the notification. This prevents a user from accidentally brushing over a NFC surface and performing an action accidentally.
