Frequency signature chipless RFID tag based on spurline resonator is presented in this letter. Resonant response of spurline is explained by analyzing the surface current distribution. Chipless tag consists of a data encoding circuit and two cross polarised monopole antennas. The tag has a data capacity of 16 bits in the range 2.13 to 4.1 GHz. Data capacity of data encoding circuit is enhanced by repositioning the spurlines. The prototype of the tag is fabricated on FR4 substrate. Developed tag can be used for cost effective identification of items in the industry.