I used Bruce Jaffe several years ago for a couple of years. He's good - he advised and sorted out some pension matters for me. He's an american lawyer, long time resident in the UK, based in NW London, and has the necessary tax/accountancy qualifications. He works with a partner who can do the UK tax end. His prices for doing tax returns were quite reasonable, certainly less than the boutique firms. You don't get tax planning, advice, explanation, etc but that could probably be arranged