General Enquiries & Auction Estimates

For general enquiries about buying and selling at Christie’s, please contact Client Service at or by telephone at +44 (0)20 7839 9060 (London) or +1 212 636 2000 (New York).

For estimate requests, feel free to use our online Auction Estimates service or contact one of our Specialist Departments directly.

Find a Specialist Near You

Find a specialist near you
Christie’s global presence is spread across a network of international salerooms and 61 representatives and offices.

Senior Management Team

  • Zita Gibson

    Head of Business Development


    Zita is Head of Estates, Appraisals & Valuations and Private & Iconic Collections, having joined Christie’s in 2007 following an MA in Classics at Trinity College, Oxford University and an MA at the Courtauld Institute of Art. She has orchestrated and overseen many multi-category proposals, pitches and collection sales, acting as the main liaison between vendors and the business throughout the valuation and sale process. Most recent highlights include The Roger Federer Collection (2021), Julians Park and Six Private Collections (2021), The Collection of Mrs Henry Ford II (2021), Alexandra Tolstoy: An Interior by Sibyl Colefax & John Fowler (2020), The George Michael Collection (2019), An Adventurous Spirit: An Important Private Collection Sold to Benefit a Charitable Foundation (2018/2019), Old Masters/New Scholars: Works of Art Sold to Benefit Rugby School (2018), Thomas Chippendale 300 Years (2018), The Collection of Raine Countess Spencer (2017) , and Christie’s 250th Anniversary Defining British Art Auction and Loan Exhibition (2016).

    Zita Gibson

    Name:Zita Gibson

    Position:Head of Business Development
  • Ruth Cornett CTA TEP

    Senior Director, Heritage & Taxation Advisory Service


    Prior to joining Christie’s, Ruth Cornett worked as a tax adviser in a number of professional firms in the City and the West End of London. After training as an art historian and working as a curator in the V&A, Ruth changed careers in 1992, studying law and qualifying as a Chartered Tax Adviser (CTA) in 1998. Ruth has advised a broad spectrum of clients on a range of tax matters with a particular emphasis on capital gains tax, inheritance tax and income tax. To consolidate her expertise in these areas, Ruth qualified as a Trust and Estate Practitioner (TEP) in 2008. Ruth lectures frequently for Christie’s Education and STEP on tax and heritage matters, has contributed to leading publications in this field and sits as an observer on the Tax and Political Committee of Historic Houses (HH).


    Name:Ruth Cornett CTA TEP

    Position:Senior Director, Heritage & Taxation Advisory Service
  • Tom Legh TEP

    Senior Director, Head of Estates, Appraisals & Valuations, EMEA


    Tom Legh joined Christie's in 2008 and is a Senior Director in the Estates, Appraisals & Valuations department. Tom has extensive experience in managing complex UK and international valuations and devising optimum strategies for selling collections and individual works at auction, privately or to the nation. Skilled at anticipating the wide-ranging needs of clients, Tom has a particular focus on the issues facing UK heritage clients, including conditional exemption claims, offers in lieu and other tax planning exercises. He has an MA in History of Art and Architectural History from the University of Edinburgh, a Graduate Diploma in Law and is a STEP qualified Trust and Estate Practitioner. This broad skillset enables Tom to help clients navigate the complex issues which arise in the international art market.

    Tom Legh TEP

    Name:Tom Legh TEP

    Position:Senior Director, Head of Estates, Appraisals & Valuations, EMEA

Account Managers

  • Miriam Winson-Alio

    Account Manager, Director


    Miriam Winson-Alio is a Director and Account Manager in London. She holds a Bachelor in Business Administration from Spain and a Postgraduate degree in Art History from Cambridge University, later gaining an M.Litt. from Glasgow University. Prior to joining Christie’s she had a successful career in Trade-Finance and was based in Switzerland. Miriam joined Christie’s in the Old Masters & 19th Century Art department in 2010, where she played a pivotal role co-ordinating some of the most successful auctions to date. In 2012 Miriam transitioned to Estates, Appraisals & Valuations and has since managed complex multi-category projects globally. Her languages and international professional experience bring wider knowledge and a broader perspective to the team.

    Miriam Winson-Alio Image

    Name:Miriam Winson-Alio

    Position:Account Manager, Director
  • Georgie Mawby TEP

    Account Manager, Director


    Georgie is a Director and Account Manager in London. Georgie joined the Christie's Heritage and Taxation Advisory Service in 2010, before becoming an Account Manager in the Estates, Appraisals & Valuations department in 2014. Georgie works with a diverse range of private clients, trusts, and estates on issues relating to the valuation of works of art and collection management. She has a particular interest in the issues facing UK heritage clients including the preparation of complex valuations for probate, negotiated sales to the nation in lieu of tax, and conditional exemption claims. Georgie has extensive experience in managing valuations of works of art in the UK and worldwide for sale at auction, private sale, and negotiated sales to museums across the UK. Georgie holds a BA (Hons) in History of Art from the Courtauld Institute of Art and is a qualified member of the Society of Trust and Estate Practitioners (STEP).

    Georgie Mawby Image

    Name:Georgie Mawby TEP

    Position:Account Manager, Director
  • David Ratcliffe

    Account Manager


    David Ratcliffe joined Christie’s in 2015 as part of the Communications Team before moving on to work in various specialist departments, including Islamic & Indian Art, Rugs & Carpets, South Asian Modern + Contemporary Art, Science & Natural History and Books & Manuscripts. Having joined the Estates, Appraisals & Valuation department as an Account Manager in 2022, David manages both UK and international valuations in preparation for auction with a particular focus on the Middle East. David has extensive experience managing the complex requirements of international clients and is versed in project management spanning various countries and jurisdictions.


    Name:David Ratcliffe

    Position:Account Manager
  • Cecilia Zi

    Account Manager


    Cecilia joined Christie’s in 2016 and is an Associated Director and Account Manager in London. Prior to her current role in the Estate, Appraisals and Valuations department, Cecilia worked as a specialist for Chinese Ceramics and Works of Art, gaining international experience at Christie’s London, New York and Hong Kong. Cecilia has managed and overseen important single-owner auctions, including Masterpieces of Early Chinese Gold and Silver (New York 2019) and Classical Chinese Furniture from the Tseng Collection (Hong Kong 2022). Holding a Bachelor's degree in Political Science and a Master’s degree in East Asian Art history from the University of Heidelberg, Cecilia gained profound experience in German auction houses before joining Christie’s London. Her vast experience and in-depth knowledge of the international auction market allow her to anticipate global market trends and support clients navigating today’s fast-paced auction world. Bilingual in Chinese and German, Cecilia oversees complex estate collections in the UK and continental Europe with a particular focus on clients from the DACH region.

    Cecilia Zi

    Name:Cecilia Zi

    Position:Account Manager