Actually, NFC readers have an “emulation mode” that enables them to behave like a tag that can be read. In this way, you could use your phone to open a door with an NFC-based access control system, or pay for a movie or bus ride by swiping your NFC phone by a turnstile. So all NFC phones can do what you are looking to do.
—Mark Roberti, Founder and Editor, RFID Journal
Can we use UHF tags and readers at other frequency ranges? »