In both JET and MAST, the Error Field Correction Coils (EFCCs) have been used recently in order to attempt to control Type I Edge Localised Modes (ELMs), which represent a major threat to the lifetime of plasma facing components in ITER. Using vacuum magnetic modelling it is suggested that the ELM mitigation observed at JET could be related to the stochastization of the magnetic field at the edge. Indeed, the onset of ELM mitigation is found to be correlated with a certain level of the Chirikov parameter profile. Initial MAST results are presented which show an effect of EFCCs on the ELMs, again compatible with edge stochastization according to the modelling. New coils dedicated to ELM control are ready for use on MAST this year and are presented here briefly.