Today we have offices in Dundalk, Newry and Belfast and employ over 30 qualified staff to service clients on an all-Ireland basis. Meet the management team looking after our client needs:

John MacMahon BComm FCA

A UCD graduate, after gaining experience in Dublin working for Arthur Andersen John founded the practice in 1982 to offer accountancy services to clients on both sides of the border.  John has particular expertise in the area of cross border business, auditing, business development and community businesses. Having served as chairman for 17 years, John is a serving board member of the pioneering community organisation Newry & Mourne Co-operative Ltd, which has an asset base of over £10 million.

John has been lobbying on behalf of cross border business for many years, succeeding on changing onerous legislation on a number of occasions.

  • All

  • Chartered Accountant, Insolvency Practitioner

  • Family Business and Cross Border Taxation


John McGinn FCA

Rostrevor native John has been a partner in the firm since 2005 and offers expertise in the areas of corporate tax planning, family business development, corporate financing and development of construction, haulage and retail businesses. John is part of the delivery teams for programmes for start up companies both north & south.

Gervase Kelly CTA ATT

As Head of Tax in our Newry office and with over 30 years experience, Gervase has extensive expertise in all aspects of taxation which allows us to provide tax planning capability normally not available outside of the large city-centre practices.

Derek Carrie FCCA

Based in our Dundalk Office, Derek is a qualified Chartered Certified Accountant and a Registered Auditor in Ireland and the UK. He trained with John MacMahon & Co, has been working with the firm since 1991. Derek has over 25 years’ experience in cross border business, accounting and taxation. Prior to becoming an accountant Derek worked in light engineering, in addition to 10 years in the agricultural wholesaling sector.

  • Dundalk

  • Certified Accountant

  • Tax


Lisa Fegan BA FCA

Lisa is a Senior Manager based in our Newry office, having joined the practice in 1998 and qualified as a Chartered Accountant in 2001. She has extensive experience in dealing with all types of accountancy and taxation matters for Companies, Sole Traders and Partnerships, many of which operate their business on a cross border basis.

Lisa has expertise in the area of business consultancy and development and has an excellent record of preparing business plans and proposals to secure grant and bank funding for all sizes and types of business.  She also has a strong network of contacts with key personnel across a wide spectrum of funding bodies.

James MacMahon BA ACA CTC

James is a qualified Chartered Accountant and Chartered Tax Consultant and has headed up our Belfast office since 2011.

James has overseen the firm’s growth in the Greater Belfast area from our launch including the move to our own premises on Hill St in 2015.

Having trained in Dublin, James has developed extensive knowledge and experience of the Irish and UK taxation systems over the past 10 years.

Assisted by a qualified team on the ground in Belfast; with support from Newry and Dundalk, James provides our Belfast clients with strategic cross border business consultancy and tax planning advice using a level of experience in this area that no other Belfast firm can match.

Claire McCullough BSc (CompSci) ACA

UCD Computer Science graduate Claire joined the practice in 2009, prior to this Claire was working as an IT Consultant for a global Management Consulting and Technology Company. Since joining the practice Claire brought her consultancy experience to deliver efficiencies for our clients.

As a Chartered Accountant Claire has experience in compliance, accounts preparation and tax in both the UK and ROI. With industry specialism in the Agri-Food, IT, Construction, Transport and Retail Sectors.

Claire is a qualified Forensic Accountant utilising both her IT and Accountancy skills to produce expert reports.

Carline Mulholland BA ACA CTA

As a qualified Chartered Accountant and Chartered Tax Adviser Carline’s focus is predominantly on corporate, personal and inheritance tax planning issues for clients as well as all aspects of tax compliance.

She also offers advice on business performance, development and general accounting compliance issues

Working with a diverse client portfolio that spans both the North and South of Ireland she has acquired industry specific knowledge in the general medical practice, food processing, engineering, gaming and book-making industries

Carline is also a Part-time lecturer with Southern Regional College in Newry in Taxation and Financial Accounting.

  • Newry

  • Chartered Accountant and Chartered Tax Adviser

  • Taxation


Monica Duffy MIATI ACA

Monica is a qualified Chartered Accountant who joined the practice in 2010. She is also a qualified member of Accounting Technicians Ireland.

In 2015 she received the Danske Bank prize for achieving first place in Northern Ireland in her Final Admittance Exams for Chartered Accountants Ireland.

Monica specialises in audit, but has extensive experience in both accounts production and taxation issues, on both sides of the border in a variety of sectors, including Retail, Engineering, Construction, Hospitality, Haulage and IT Consultancy. One of her main focuses in the practice is on technical compliance, review and reporting, providing guidance both in house and externally to clients to ensure that all reporting regulations and legislation are adhered to.

Orlaith MacMahon BA MSc ACA

Orlaith is a qualified Chartered Accountant and a manager in our Newry office.  Having originally trained in Dublin and subsequently joining the practice in 2009, she has an extensive experience in accounts preparation, compliance and general tax affairs both North and South of the border. She also has a broad range of auditing experience and assists in the compliance review process of all our limited company accounts. She has particular industry experience in the areas of retail, professional services, and agriculture.

Lisa Magee BSc FCCA

Lisa has been with the practice for over 15 years in the Newry office.  As head of the audit department Lisa has extensive expertise and experience in Auditing clients from various business sectors. Lisa plays a key role in technical compliance and has strong knowledge on Financial Reporting in both NI and ROI.

Frances Matthews BSc FCCA

Frances has been with the practice since 2004 and spends her time working on both sides of the border. This has given her extensive knowledge and experience in dealing with all aspects of crossborder tax and business. Frances is a key member of our audit team and has vast experience in auditing a wide variety of our clients, including retail, pharmaceutical, haulage and construction.

Paul Kearney BA ACA

A graduate of Queens University Belfast and a qualified Chartered Accountant, Paul has worked for the practice for over 15 years.

Paul has extensive knowledge of cross border taxation issues, delivering a range of taxation services to clients across many sectors, acquiring particular expertise within the Agri and Construction Industries of both the UK and Ireland.

Advising on all aspects of accounting, taxation and finance, Paul is passionate about customer service and is focused on the provision of business development and the implementation of tax planning strategies for owner managed businesses.

In addition, Paul deals with all levels of HMRC enquiries and has specific experience and knowledge of VAT & Corporate tax, specialising in case resolutions minimising the interruptions that any form of tax investigation causes to an individual’s life and business.

Amy Magennis MIATI

A qualified Accounting Technician, Amy has worked in our Newry office since 2008.

Amy has a vast knowledge of accounting software, particularly in well-known packages Sage and Xero. She provides bespoke software training to staff and clients, focusing on client education and the maximisation of accounting resources. Amy is also a lecturer in the School of Business & Management for Southern Regional College.

Amy has particular experience in dealing with Start-Up companies, her specialism with Start-Ups has helped clients successfully avail of the generous Research & Development tax incentives. As an industry specialist in both the construction and haulage industries Amy has a breadth of knowledge in UK & Irish payroll and construction industry taxes and can assist clients with all aspects of cross border compliance. As a qualified International Transport Manager she also liaises with clients on compliance matters within the haulage industry

Why Work With Us?

Trusted by some of the biggest brands…

John MacMahon & Co offers graduates and trainees great opportunities to develop their skills and work with a growing team of professionals. Our staff members are recruited locally and not only benefit from flexible, family-friendly working conditions but also receive ongoing training to constantly improve the service we offer to our clients.

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