International Tax Training, Designed Around Your Team

Cross-border work is where tax gets hardest — and where confident, well-trained teams stand out. We design bespoke international tax training for professional services firms, expanding businesses and multinationals, built around your clients, your markets and your people.

Please get in touch to discuss your team's needs.
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Trusted International Tax Training

ExtraTax Training delivers bespoke international tax training across the UK, Ireland and EMEA — from foundations in double tax treaties, residence and permanent establishment through to multi-year development partnerships and international tax conferences for global networks. Our team supports tax professionals in more than 40 countries.

The problem we solve

International tax expertise is in demand everywhere: clients expect seamless multi-jurisdictional advice, regulations keep multiplying, and cross-border issues now reach teams that were once purely domestic.

But genuine international tax capability is hard to build. The technical ground is wide — including the application of double tax treaties, residence, permanent establishment, withholding taxes, anti-avoidance regimes — and the partners who hold that knowledge rarely have time to teach it.

We design and deliver the training, drawing on first-hand experience from practice, industry and tax authorities. Your team builds real cross-border capability while your senior people stay focused on clients and growing your business.

How we work with you

We don't arrive with a fixed syllabus. Every engagement starts with a conversation about your team and your business, and the programme is designed from there.

Understand

Your team's experience levels, the jurisdictions and treaty networks that matter to your client base, and the cross-border issues they actually face — inbound, outbound or both.

Design

A programme built around those needs — the right topics, the right depth, the right format. We agree the outline with you and refine the materials with your input.

Deliver

Online, in person or hybrid, in the locations and time zones that suit your team. Sessions are interactive and case-study led. Participants apply treaty articles to scenarios, work through cross-border case studies in small teams, and present their advice to a "client".

Refine

Feedback from participants and leadership shapes the programme as it runs. And as our longest-standing client relationships with Top 10 firms show, the best programmes evolve year on year.

What a bespoke programme can look like

Our work with Grant Thornton shows how international tax training can grow with a client, from a single-office programme to a pan-European partnership.

A multi-year partnership with Grant Thornton

2023 — building local capability. We delivered a bespoke international tax programme for Grant Thornton Northern Ireland, covering core topics including double tax treaties, residence, permanent establishment, CFCs and the Corporate Interest Restriction. Working closely with the international tax director, we combined in-person teaching with practical case studies to develop the team's technical and client advisory skills.
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"The ExtraTax Training team delivered a number of excellent international tax training sessions, worked around our business needs and generously shared a huge amount of information. The most impressive part of the training for me though was the mix of theory and first-hand experience — covering Practice, Industry and Tax Authority points of view. I couldn't recommend the services of ExtraTax Training highly enough."
Jonathan Megaw, International Tax Director, Grant Thornton (NI) LLP
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2024 — going international. Grant Thornton International commissioned a multi-format programme for manager-level professionals across its EMEA network — online sessions, detailed case studies and in-person training in Düsseldorf — strengthening international tax and transfer pricing expertise across member firms.
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2025 — a European tax conference. The programme evolved into Grant Thornton International's European Tax Conference in Dublin. A two-day intensive event designed around a pan-European case study written by ExtraTax Training, combining technical updates with client engagement scenarios across VAT, global mobility, international tax and transfer pricing.
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2026 — a tax team development partnership. We now deliver a Corporate International Tax Programme for Grant Thornton Ireland and Northern Ireland, developing assistant managers to associate directors across both offices through in-person modules and a group case study.
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Inside a corporate international tax programme

A typical modular programme pairs concepts with application. International tax modules cover jurisdiction to tax and the OECD Model Tax Convention, residence and permanent establishment, and topical issues such as BEPS 2.0, with participants applying treaty articles to cross-border scenarios.

These combine with domestic international provisions (e.g. the UK's Corporate Interest Restriction and hybrid rules; Ireland's Interest Limitation Rule and dividend participation exemption), advisory skills modules on legislative research, technical writing and client communication, and extended case studies. For example, advising an expanding business on cross-border flows and repatriation, assessing residence and PE risk, and handling a cross-border tax audit.

Where a programme calls for additional specialist expertise, e.g. Irish international tax, US tax, EU VAT, we work with trusted associate trainers, including former senior tax authority officials, who share our practical approach.

These are examples, not a menu. Your programme might be foundations for a team new to cross-border work, specialist modules for an established international tax practice, a conference for a network — or a pathway that grows across several years. The starting point is always your needs, not our template.

Topics we cover

Our core team, supported by specialist associate trainers, can design and deliver training on a wide range of UK and Irish corporate tax topics, including:
  • OECD and UN Model Tax Conventions
  • Application of double tax treaties
  • Double tax relief
  • Corporate residence
  • Permanent Establishment (PE)
  • Withholding taxes (WHT)
  • Controlled foreign companies
  • Hybrid mismatch rules
  • Interest limitation rules, including CIR
  • BEPS project and BEPS 2.0
  • EU Direct Tax Initiatives
  • UK/Ireland cross-border tax issues
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For US international corporate tax, we run a renowned specialist workshop with Narelle MacKenzie of San Diego State University — Introduction to US International Corporate Tax. For transfer pricing, see our dedicated transfer pricing training. 

For individuals and sponsored cohorts seeking a qualification, our online ADIT courses cover Principles of International Taxation and six further modules.

Your tutors

International tax programmes are led by Catriona Loughran FCA CTA ADIT CTC, Founder and Managing Director, with over 25 years' experience across global accounting firms, multinational groups and HMRC. In HMRC's Large Business team she examined the tax affairs of the UK's largest groups, and she represented HMRC at the OECD, delivering a capability-building programme to 14 tax authorities across Asia and Africa. In 2008, she was the first person in Ireland to gain the CIOT's ADIT qualification.

Catriona Loughran

Founder and Managing Director

Linda Mercel

Director of Tax Training and Learning

Alyson Sutcliffe

Tax Training Manager

Why choose ExtraTax Training

Designed around you

Your jurisdictions, your client scenarios, your team's experience levels — the programme is built to close your gap, not deliver our syllabus.

Diverse perspectives

Our tutors have advised clients and worked in-house, meaning training covers not just what the rules say, but how they play out on all sides of a cross-border issue.

Proven at every scale

From a single-office programme to a pan-European conference for a global network, developing partnerships that deepen year on year.

Immediate business impact

Teams that can spot cross-border issues, research them independently and explain them clearly to clients — strengthening multi-jurisdictional delivery and your firm's reputation.
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Others deliver courses. We develop careers.

Frequently asked questions

Is this a fixed course or is it tailored to our firm?

Every programme is tailored. We design the topics, depth, format and schedule around your team, your client base and the jurisdictions that matter to you. The Grant Thornton story on this page shows how a programme can start with one office and grow into a multi-year, multi-country partnership.

Who is international tax training suitable for?

Anyone whose work touches cross-border issues: corporate tax teams taking on international work, established international tax practices deepening specialisms, in-house teams in multinationals, and finance professionals who need to recognise the issues. Content is pitched to the participants in the room.

Can you deliver across multiple offices or countries?

Yes. We have delivered programmes across Grant Thornton International's EMEA network, designed a pan-European conference case study, and regularly teach cohorts spanning several countries and time zones, online and in person.

Do you cover Pillar Two?

At present, we provide awareness-level overviews of Pillar Two and BEPS 2.0 — what the rules are, who they affect and what they mean in practice — as part of broader international tax programmes.

Do you cover UK–Ireland cross-border issues?

Yes — it's a particular strength. Based in Belfast and working across both jurisdictions, we train teams on the corporate tax, income tax, social security and VAT implications of businesses and employees operating across the UK–Ireland border.

Can the training lead to a qualification?

Yes. Bespoke programmes can incorporate or progress to ADIT modules, including Principles of International Taxation and Transfer Pricing, giving your team an internationally recognised credential. Our ADIT students achieved 100% pass rates in five of seven modules across the 2025 exam sittings.

How interactive are the sessions?

Very. Participant numbers are capped, sessions are built around exercises and discussions, and larger programmes include group case studies where teams produce deliverables and present to a "client". We find this is what turns knowledge into capability.

How do we get started?

Contact us to arrange a call. Tell us about your team and the cross-border work they handle, and we'll come back with a proposed programme designed around your needs.

Please get in touch with any questions on bespoke international training for your team.

A member of our team will respond to your query as soon as possible.
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Alternatively, contact us by email or phone.
info@extrataxtraining.com
+44 (0)28 9590 5990
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