Why does the oyster card on the back of my phone start ringing when I touch it?

[WPCentral Question]

The oyster card and my lumia 930

When I touch my oyster card of my back of my phone its start ringing (for 1 or 2 seconds) but It doesn't do anything. What's the problem? Any idea?

 

[NICK TOALE]

Re: The oyster card and my lumia 930

NFC is switched on in your phone. Oyster cards use NFC to communicate