Was talking to a chap recently who has moved to the UK from Sweden with his XJS, he told me it was a year to get British plates. Presumably you need UK insurance from day 1, since [his] Swedish insurance would only give him holiday use in the UK (hence would not include commuting, business use etc), and UK MoT from whenever the Swedish one expires. Not sure about Road Tax - given the recent changes in UK law about tax ending as soon as a vehicle is sold I imagine UK VED is payable from day 1 as well.