In this paper the concept of ‘Regal Electrochemistry’ is expanded towards the electrochemical sensing of Novel Psychoactive Substances (NPSs) namely synthetic cathinone derivatives where British coinage is used as the electrochemical sensor. In this proof-of-concept approach, the electrochemical sensing of mephedrone (4-MMC) and 4′-methyl-N-ethylcathinone (4-MEC) is shown to be possible using a British 1 pence coin for the first time. This novel electrochemical protocol is validated towards the detection of cathinone derivatives in a seized street sample that has been independently analysed via high performance liquid chromatography demonstrating its potential use as a novel electrochemical sensor for NPSs.