A new multiband Ultra High Frequency (UHF) Radiofrequency Identification (RFID) sensor tag for industrial applications is proposed. The principle relies on a very simple operation: the effect of flipping the tag itself on a metallic surface for operation either in the European Telecommunications Standards Institute (ETSI) or the Federal Communication Commission (FCC) UHF RFID frequency bands. Moreover, the tag design aims an optimization for operation on metallic objects and maintains a small form factor. An analysis based on the equivalent circuit of the antenna impedance considering the two positions explains the physical concept and shows the impact of the metallic surface on the resonance frequency of the RFID sensor tag. Measurement results demonstrate a read range up to 3 m for ETSI and FCC UHF RFID frequency bands when the sensor tag is operating on metallic surface.