Where do I hold my phone to tap?

iPhone

Wake it, then hold the top edge, near the camera, against the object. Tap the banner that appears.

Android

Wake it and check tag reading is switched on (it sits next to contactless payments in Settings). Hold the middle of the back against the object. The page opens by itself.

Keep the phone still for a second or two. If the tag is small, move the phone slowly across the object. It may be in a corner, a label or a hem.

The tag has no battery and nothing to charge. It takes the tiny bit of power it needs from your phone.