A near field communication (NFC) system may include an NFC tag comprising a memory configured to store geo position data corresponding to a geographic position of the NFC tag and a first NFC sensor coupled to the memory and configured to initiate a transaction based upon NFC communications. The NFC system may further include a mobile wireless communications device comprising a second NFC sensor and a controller coupled thereto. The controller may be configured to establish NFC communications with the first NFC sensor when in proximity thereto and retrieve the geo position data therefrom authenticate a geographic position of the NFC tag based upon the retrieved geo position data and perform the transaction with the NFC tag if the geographic position of the NFC tag is authenticated.