John MacMahon

Business Details

44 Years

experience

Chartered Accountants & Cross-Border Tax Experts

Established in 1982, John MacMahon is a chartered accountancy practice with offices in Belfast, Newry, and Dundalk. Our team of over 30 qualified professionals specialises in cross-border taxation and compliance, serving clients across Ireland and the UK. We provide tailored accountancy, audit, and business advisory services to family-owned businesses, start-ups, and enterprises in sectors including construction, agriculture, and retail. Our cross-border expertise addresses complex tax regimes in both jurisdictions, supported by deep sector knowledge and a commitment to client-centric solutions. With decades of experience, we combine local insight with international standards to deliver strategic financial guidance.

Our services extend to forensic accounting, grant applications, and business succession planning, ensuring comprehensive support for growth-oriented clients. We maintain strong relationships with regulatory bodies and funding authorities to maximise client opportunities. Our approach prioritises transparency, technical excellence, and proactive communication to meet evolving business needs. Through regular client seminars and updates, we ensure clients remain informed of legislative changes affecting their operations. Backed by Chartered status and audit registration, we deliver trusted expertise to businesses navigating cross-border challenges.

Services

Accounting & Audit Tax Planning Business Advisory Grant Applications Forensic Accounting

Details

Year established: 1982

Highlights and features

We offer 40+ years of cross-border tax expertise since 1982
Our team holds Chartered Accountant and Registered Auditor status
Specialised in grant funding applications across Ireland and UK
Tailored advisory services for family-owned businesses and start-ups
Proven track record in forensic accounting and business succession planning

Associations and certifications

Chartered Accountants Ireland
Audit Register UK

What people say

Expert cross-border tax knowledge Proactive business advice Successful grant applications Experienced team Tailored solutions

Website

Update Listing

Services

Accounting & Audit

We provide comprehensive accounting and audit services for businesses of all sizes across Ireland and the UK. Our team ensures compliance with statutory requirements while enhancing financial processes. Specialising in sectors like construction and agriculture, we deliver audits that improve business performance through detailed analysis and strategic recommendations.

Tax Planning

Our cross-border tax expertise addresses complex UK and ROI compliance regimes. We offer strategic planning to minimise liabilities while ensuring regulatory adherence. Services include corporate tax, VAT returns, and inheritance tax planning, supported by insights typically found in major city practices.

Business Advisory

We deliver tailored advisory services covering corporate finance, succession planning, and grant applications. Our approach combines sector-specific knowledge with practical solutions for business growth. This includes forensic accounting support and strategic guidance for mergers and acquisitions across jurisdictions.

Grant Applications

We specialise in identifying and securing grant funding for business development projects. Our team manages applications for capital expenditure, job creation, and R&D initiatives on both sides of the border. We maximise success rates through expert documentation and regulatory navigation.

Forensic Accounting

Our forensic team provides expert analysis for fraud investigations, matrimonial disputes, and business valuations. We deliver court-compliant reports and expert witness testimony, combining investigative skills with deep accounting knowledge to resolve complex financial matters.

People

John MacMahon

Managing Partner

BComm FCA, founder with 40+ years' experience in cross-border accountancy. Leads strategic direction and client relationships across all offices.

John McGinn

Partner

FCA qualified with specialist expertise in audit and corporate compliance. Oversees technical standards and regulatory adherence for the practice.

James MacMahon

Partner

BA ACA CTC with focus on tax planning and cross-border compliance. Provides strategic guidance on complex taxation matters for multinational clients.

Lisa Fegan

Associate Director

FCA qualified with responsibility for client portfolio management. Specialises in business advisory services and financial restructuring proposals.

Gervase Kelly

Associate Tax Director

CTA ATT qualified tax specialist. Leads cross-border tax planning initiatives and advises on inheritance tax and investment strategies.

Questions

What cross-border services do you offer?

We specialise in UK and ROI tax compliance, dual jurisdiction audits, and grant funding applications across Ireland and the UK.

How do you support start-up businesses?

We provide business planning, grant application assistance, and tax-efficient structuring tailored to new ventures' specific needs.

Can you help with forensic accounting matters?

Yes, our team handles fraud investigations, business valuations, and court-compliant financial analysis for legal proceedings.

What sectors do you specialise in?

We focus on construction, agriculture, retail, and family-owned businesses with cross-border operations.

Do you offer audit services for large corporations?

We audit businesses of all sizes, with specialist experience in engineering, food processing, and haulage industries.

How do you handle grant applications?

We identify eligible programmes, prepare documentation, and manage submissions to maximise funding success for clients.

Reviews (4)

Write a Review

Alan Mckendry

Aug 25, 2021 Report

Our business was growing and we were aware that we needed not just an Accountant but a company that could provide us with a full professional accountancy service plus all round business advice. John MacMahon & Co. were recommended and that introduction was pivotal to the growth and future success of our business. The input and advice from John McGinn and his team helped us realise what was possible and begin to plan the next steps Without their experience, and expertise we would not have been able to grow our business in the way that we did. This combined with a very professional and accurate accountancy service enabled us to change the structure of the company which gave us many more opportunities. Alan and Maura McKendry

Bjmulvaney

Jun 17, 2021 Report

As a client who has been involved with John MacMahon for almost 30 years I cannot recommend them highly enough. Specifically working with John McGinn and staff who have looked after company accounts, researched and given great business advice in a professional yet friendly manner. If you are a small business, large enterprise or startup - you will find the accounting support you need with John MacMahon & Co

Stephen Bullock

Jun 05, 2021 Report

I have been a client of John MacMahon & Co for a number of years and have always found John and his team to be extremely helpful and professional in offering sound advice that has helped me greatly in both running and growing a successful business. The people I was in contact with were always very knowledgeable within their area of expertise, a pleasure to work with and nothing was ever too much trouble. I would have no hesitation in recommending John MacMahon & Co to any prospective business owner that requires a Financial Accountant/Auditor.

Bridal By Seven Newry

May 21, 2021 Report

John & team at John MacMahon & Co have been invaluable to us during the startup and operation of our business. Their team is polite, professional and approachable and their knowledge of all financial and tax aspects is second to none - all communicated in a way that helps us understand and feel more confident in managing our business.