In this paper, a compact 13-bit fully passive chipless RFID tag is presented. The overall size of the proposed chipless tag is 16.65 mm x 17 mm. The resonating structure is loaded with thirteen C-shaped nested slots. The presented tag is optimized and analyzed for three distinct substrates that are, Rogers RT/duroid®/5870, Taconic TLX-0 and Rogers RT/duroid®/5880. The articulated tag structure possesses the capability of generating 213= 8192 exclusive IDs for low-cost identification of various objects. Flexibility is achieved using Rogers RT/duroid®/5880 substrate over the aspired frequency band of 3 GHz - 12 GHz. Hence, the robust chipless tag is an ideal choice to be deployed on curved surfaces for different cost effective IoT based industrial applications.