An apparatus includes an NFC circuit and an electrically conductive layer. The NFC circuit includes an antenna configured to inductively couple to signals emitted by another NFC circuit, a charging circuit configured to output power provided by the inductive coupling through the antenna to the signals emitted by the other NFC circuit, and a transceiver circuit configured to be powered by the charging circuit to transmit data for receipt by the other NFC circuit. The electrically conductive layer is removable from being on the NFC circuit, and while the electrically conductive layer is on the NFC circuit the transceiver circuit is prevented from transmitting. The electrically conductive layer can include a removable conductive sticker that electrically connects to one or more locations on the antenna, to a ground plane of the NFC circuit, and/or to another circuit node of the NFC circuit to prevent the transceiver circuit from transmitting.