International Tax Training, Designed Around Your Team
When business crosses borders, the tax questions multiply, and 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.
Trusted International Tax Training
The problem we solve
Cross-border tax issues no longer sit only with specialist teams. Clients expect their advisers to handle international questions as confidently as domestic ones. As businesses expand overseas, teams that were once purely domestic find cross-border issues landing on their desks.
But genuine international tax capability is hard to build. There is a lot of ground to cover, from applying double tax treaties and assessing residence and permanent establishment risk to withholding taxes and anti-avoidance rules. And the people in your business who hold that knowledge can rarely find the time to teach it.
We design and deliver the training for you, drawing on first-hand experience from practice, industry and tax authorities. Your team builds cross-border capability while your senior people stay focused on clients and growing your business.
But genuine international tax capability is hard to build. There is a lot of ground to cover, from applying double tax treaties and assessing residence and permanent establishment risk to withholding taxes and anti-avoidance rules. And the people in your business who hold that knowledge can rarely find the time to teach it.
We design and deliver the training for you, drawing on first-hand experience from practice, industry and tax authorities. Your team builds 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, whether inbound, outbound or both.
Design
A programme built around those needs, covering the right topics at the right depth, in a format that works for your team. 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 practical and interactive. 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 one office 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 topics such as 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.
We delivered a bespoke international tax programme for Grant Thornton Northern Ireland, covering topics such as 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.
2024: Going international
Grant Thornton International commissioned a programme for manager-level professionals across its EMEA network, combining online sessions, detailed case studies and in-person training in Düsseldorf to strengthen international tax and transfer pricing expertise in member firms.
Grant Thornton International commissioned a programme for manager-level professionals across its EMEA network, combining online sessions, detailed case studies and in-person training in Düsseldorf to strengthen international tax and transfer pricing expertise in member firms.
2025: A European tax conference
The programme evolved into Grant Thornton International's European Tax Conference in Dublin. The two-day event was 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.
The programme evolved into Grant Thornton International's European Tax Conference in Dublin. The two-day event was 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.
2026: A tax team development partnership
We now deliver a Corporate International Tax Programme for Grant Thornton Ireland and Northern Ireland, developing professionals from assistant managers to associate directors across both offices through in-person modules and a group case study.
We now deliver a Corporate International Tax Programme for Grant Thornton Ireland and Northern Ireland, developing professionals from assistant managers to associate directors across both offices through in-person modules and a group case study.
Inside a corporate international tax programme
No two programmes look the same. Yours 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 a conversation about what your team needs.
Topics we cover
Our core team, supported by specialist associate trainers, can design and deliver training on a wide range of international tax topics, including:
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OECD and UN Model Tax Conventions
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Application of double tax treaties
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Double tax relief
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Corporate residence
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Permanent Establishment (PE)
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Withholding taxes (WHT)
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Controlled foreign companies
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Hybrid mismatch rules
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Interest limitation rules, including CIR
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BEPS project and BEPS 2.0
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EU Direct Tax Initiatives
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UK/Ireland cross-border tax issues
For US international corporate tax, Narelle MacKenzie of San Diego State University has delivered her intensive three-day course with us since 2024 - Introduction to US International Corporate Tax. For transfer pricing, please see our dedicated transfer pricing training.
For team members working towards a qualification, our online ADIT courses cover Principles of International Taxation and six further modules.
For team members working towards 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 Catriona examined the tax affairs of the UK's largest groups, and she has taught international tax to tax authority officials at an OECD training programme in South Korea. In 2008, she was the first person in Ireland to gain the CIOT's ADIT qualification.
Catriona is supported by Alyson Sutcliffe CA CTA, who brings almost 30 years' experience in UK corporate and international tax, and by a small group of trusted associate trainers, including former senior tax authority officials.
Catriona is supported by Alyson Sutcliffe CA CTA, who brings almost 30 years' experience in UK corporate and international tax, and by a small group of trusted associate trainers, including former senior tax authority officials.
Catriona Loughran
Founder and Managing Director
Alyson Sutcliffe
Tax Training Manager
Why choose ExtraTax Training
Designed around you
Your jurisdictions, your client scenarios, your team's experience levels. We build the programme around all three.
Diverse perspectives
Across our team, we have advised clients, managed tax in-house and worked for a tax authority. Training covers how the rules play out on all sides.
Lasting relationships
Clients come back year after year. Programmes that began as a single course have grown into partnerships spanning offices and countries.
Building advisers
Knowing the rules is the start. Your team learns to research the legislation, apply it to the client's facts and give advice the client can act on.
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?
We provide awareness-level overviews of Pillar Two and BEPS 2.0 as part of broader international tax programmes, covering what the rules are, who they affect and what they mean in practice.
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 have achieved consistently high pass rates, including 100% in multiple modules at recent 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".
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.