Mark O'Riordan (Chairman & Chief Executive)

Mark joined Meridian in 1998 and was appointed Chairman and Chief Executive in October 2004. As CEO, Mark guides decision making and policy making, setting the tone for the company's values, ethics and culture. Prior to this he was Operations Manager at BBL Finance Ireland, an international merchant bank based in the International Financial Services Centre in Dublin. Since 1998, Mark has held a variety of executive positions within Meridian, namely Operations Director, Managing Director North America, Client Services Director EMEA and Director of Business Services, Mark also had responsibility for the Groups Treasury requirements during this time. Mark took over the position of Chairman and Chief Executive in 2004 having acquired a vast knowledge of the business and the company. Mark is passionate about the business Meridian is involved in and personifies Meridian's commitment to delivering the highest quality services to its clients around the world. Mark is a qualified Chartered Accountant (FCA) and holds an MBA from The Open University.


Gareth Davies (Managing Director, Europe, Middle East, Africa)

Gareth was recruited in June 2001 as Managing Director of the EMEA sales region and is based in the London office. He has over twenty years experience in sales, marketing and general management having previously worked in senior sales and marketing positions in Motorola, where he was director of sales and marketing for the EMEA region, Airtech (global head of sales and marketing), Metro Media Fiber Network (general manager of the western European operations) and most recently Madge.web, where he was global head of sales. He has a B.Sc. in Managerial and Administrative Studies.


Paul Quigley (Director, International VAT Consulting)

Paul Quigley is Director of International VAT Consulting with Meridian Global Services. He started his career in VAT as an inspector with the UK tax authorities, HM Customs & Excise, in London. He then went on to work for KPMG in London, where he specialised in retail, manufacturing and international VAT. Prior to joining Meridian, Paul was working for Deloitte in London, Moscow and Prague. He now specialises in the provision of international VAT advice and related services to a broad range of Meridian's multi-national clients.


Grainne Shankey (Director, HR World-wide Operations)

Grainne joined Meridian in 1996. Previously she held various HR positions with Sullivan Bluth Studios, Wellman International, and Tara Mines. Grainne has been responsible for the HR function in Dublin since 1996 and in October 2001, was appointed director of HR Operations Worldwide. Grainne has a diploma in Personnel Management and is a Graduate Member of the Institute of Personnel Development.


Adam Smith (Commercial Director - Managed Services)

Adam is the Commercial Director responsible for Meridian’s Outsourcing and Travel & Expense services. He has over 15 years’ successful experience delivering best-in-class technical solutions supported by practical managed outsourced services both near and off-shore. Previously Adam was a Founder Director at Zero Octa, a niche travel services outsource organisation with over 600 staff across Europe, South America and Asia. Following the successful trade sale of Zero Octa he joined Interglobe Technologies as the EMEA VP for Sales and Marketing, splitting his time between the UK and Asia. Returning to live full-time in the UK, Adam joined Meridian in 2009 and now manages the global commercial and account management teams.


Derek O'Brien Chief Operating Officer Tax Technology

Derek was appointed Chief Operating Officer Tax Technology in 2018 with responsibility for leading the Tax Technology business and continues to have responsibility for the Group marketing activities in Meridian. Derek joined Meridian in March 2001 and has held several management positions during his time with Meridian including Chief Marketing Officer. He began his career with Ireland’s largest retailer Dunnes Stores in several operations management positions. Derek is a Graduate member of the Marketing Institute of Ireland (MMII Grad).


Michelle Lang (Director, International VAT Consulting)

Michelle Lang is a Director of Consulting with Meridian Global Services and is based in our Dublin office. Michelle provides support and VAT advice on issues relating to Meridian clients operating in multiple EU jurisdictions across a broad range of industries, including the pharma and manufacturing sectors. Michelle has over 15 years’ experience in VAT having worked with Deloitte prior to joining Meridian in 2013. Michelle holds a degree in Finance and is a qualified member of the Institute of Taxation in Ireland.


Sinead Gilleran (Director, International VAT Consulting)

Sinead is Director - International VAT Compliance. She joined Meridian in February 2001 as Quality Manager and has held various positions within Meridian since then including Client Service Director EMEA. Prior to Meridian, Sinead had several years experience in the development, implementation and management of Quality Systems having worked in QA Management roles including corporate Quality Manager in the British Standards Institution in London. She also holds a BA (hons) from University College Dublin.