The scope of this Technical Report is to explore developments in the use of mobile phones as RFID interrogators. It uses as a datum the communication protocols developed for near field communication, which have a defined level of security. This Technical Report will explore known developments in the use of mobile phones as RFID interrogators including (but not limited to): — extending NFC phone capabilities to read RFID tags compliant with ISO/IEC 15693 and ISO/IEC 18000-3 Mode 1; — using mobile phones as interrogators for UHF tags based on ISO/IEC 18000-6 Type C; — the development of multi-protocol readers capable of switching between high frequency and UHF. The objective of the Technical Report is to identify specific characteristics associated with mobile phones being used as interrogators with tags that are primarily intended for other purposes. It will identify some potential threats associated with the technology. It will also identify gaps in the standardization process that might need to be addressed to mitigate against such threats. To counterbalance any negative implications, the Technical Report also identifies real and potential applications that could lead to an accelerated take-up of RFID and the Internet of Things through mobile phones being used as RFID interrogators by individual citizens and organizations.