Surfactant systems responsive to pH, temperature, CO2, and light are known. Our new work has shown for the first time, magneto-responsive surfactants (also being ionic liquids ILs) introducing a new class of magnetic ionic liquid surfactants (MILSs). These MILSs are of great interest as they exhibit both amphiphilic behaviour and are magnetically active. Hence, they have novel potential applications, for example non-invasive recovery of ILs from reaction mixtures, facile separations and targeted delivery etc. Water-in-oil (w/o) microemulsions stabilized by these MILSs have now been prepared and phase stability diagrams mapped. To elucidate internal domain structures, and to determine any structural responses to applied magnetic field, it is now necessary to run contrast variation SANS experiments.