I did exactly this yesterday, in the aircraft ATP_Al flew until Friday (good luck on the type rating, mate!). We were talking to Wattisham, with FIS, when I entered cloud at the level she had asked me to fly, so I just asked for a RIS (could have gone for RAS, but wasn't really necessary). No problem with that, and she looked after all my needs until I chopped to Southend, whom she also kindly gave my details.