RFID blocking: what the shield in your wallet actually does

Contactless payment works because the card answers a radio signal as soon as it gets close enough to a reader. That very property is the reason RFID blocking exists.

The principle

Inside the wallet there is a conductive layer that shields the radio field. As long as the cards are in it, no signal reaches them, and they do not answer. It is not a chip and not electronics — it is simply material.

What that means day to day

When you pay, you take the card out and it works exactly as normal. Inside the wallet it is silent. You notice nothing of the shielding, except that the card stops responding while it is tucked away.

How big is the risk, really?

Honestly: reading a card through a bag is laborious, and the amounts that go through without a PIN are limited. The protection is a cheap precaution rather than a defence against a daily threat. Since it costs nothing and gets in the way of nothing, there is little reason to skip it.