How Do I Deactivate an RFID Tag?
kill function. If you know the security code that you need to transmit to the tag, you can send that code and deactivate it. If you don't have the code—or if it is a passive high-frequency (HF) or low-frequency (LF) tag—then the best way to deactivate it is to zap it with electricity. - See more at: http://www.rfidjournal.com/blogs/experts/entry?10845#sthash.Jy3Gwa9w.dpuf