Grant Thornton Isle of Man

What Grant Thornton Isle of Man does

Grant Thornton Isle of Man is a professional services firm established in 1987, operating from Douglas, Isle of Man, as a member firm of Grant Thornton International Ltd (GTIL). The firm employs 26 people locally and is integrated into Grant Thornton Ireland, which has nearly 3,000 people across offices in Dublin, Belfast, Cork, Galway, Limerick and the Isle of Man. The global Grant Thornton network comprises 73,000 people across 149+ countries. The firm delivers three core service lines: Audit & Assurance, Tax, and Advisory, with deep specializations in regulated Isle of Man financial services (funds, insurance, pension schemes, trust service providers), aviation advisory (managing 700+ aircraft MSNs), fintech, and sustainability/ESG. Following a January 2025 reorganization, Grant Thornton Ireland operates as an alternative practice structure, with audit and non-audit entities legally separated.

Name

Grant Thornton Isle of Man

Legal name

Grant Thornton Isle of Man

Website

https://grantthornton.co.im

Company type

Private

Operating status

Operating

Headcount range

11–50 employees

Short description

Grant Thornton Isle of Man is a 26-person professional services firm in Douglas delivering audit, tax, and advisory services to regulated financial services, aviation, and fintech clients, operating as a member firm of Grant Thornton International's global network spanning 149+ countries.

Ownership category

akta.pro rank

Product category

Professional Services — Audit, Tax and Advisory

NAICS

Offices of Certified Public Accountants (541211), Trusts, Estates, and Agency Accounts (525920)

akta.pro primary industry

Audit & Assurance Services (BPAHABAA)

akta.pro secondary industries

Financial Reporting & Technical Accounting Advisory (GAAP/IFRS) (BPAHABAF), Estate, Gift & Trust Valuation (BPAHANAL)

Keywords

• Audit and assurance
• Tax advisory services
• Business advisory consulting
• Risk advisory services
• Forensic accounting services

Headquarters

HQ city

Douglas

HQ country

Isle of Man

Offices6 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Marketing or Sales, Infrastructure

Revenue model

1. Audit and Assurance Services: Financial statement audits for entities operating in the Isle of Man economy including funds, insurance companies, pension schemes, trading companies, corporate and trust service providers and education. Revenue generated through professional fees for audit engagements.
2. Tax Advisory and Compliance: Corporate tax, personal tax, international tax, indirect tax advisory and compliance services. Includes tax planning, economic substance analysis, and tax compliance for multinational groups.
3. Advisory Services: Business risk services, consulting, financial accounting and advisory services (FAAS), forensic accounting, fintech advisory, sustainability advisory. Includes internal audit, risk advisory, change management, finance transformation, operational excellence.

Go-to-market motion2 records

Distribution channels3 records

Marketing channels5 records

Core offering

Grant Thornton Isle of Man is a professional services firm providing Audit & Assurance, Tax, and Advisory services to Isle of Man-based and international clients. Services cover financial statement audits for funds, insurance companies, pension schemes, and trust service providers; corporate, international, private client, and indirect tax compliance and advisory; and advisory sub-services including business risk, forensic accounting, consulting, fintech, aviation, sustainability, and FAAS engagements. Clients are predominantly regulated financial services entities, aviation companies, fintech firms, mid-market enterprises, and public sector bodies.

Product overview

Grant Thornton Isle of Man is a professional services firm offering a unified portfolio of three core service lines: Advisory Services, Audit & Assurance, and Tax Services. The Advisory Services line encompasses specialized sub-services including Business Risk Services, Financial Accounting and Advisory Services (FAAS), Forensic Accounting, Consulting, Fintech Advisory, Aviation Advisory, Risk Advisory, and Sustainability Advisory. The Audit & Assurance service provides independent audit services for various Isle of Man entities across regulated sectors. The Tax Services line covers company tax, international tax, private client tax, indirect tax advisory, and global mobility services. Together, these services are designed to support clients from domestic and multinational enterprises across the Isle of Man's financial services ecosystem.

Differentiator

Problem solved

Functional benefit

Products and services

• Audit & Assurance Independent financial statement audits for funds, insurance companies, pension schemes, trading companies, corporate and trust service providers, and education sector entities operating in the Isle of Man economy.
• Tax Services Expert-led tax advisory and compliance services including company tax, international tax, private client tax, indirect tax advisory and compliance, and global mobility services for Isle of Man-based and international clients.
• Advisory Services A broad portfolio of advisory services including Business Risk Services, Financial Accounting and Advisory Services (FAAS), Forensic Accounting, Consulting, Fintech Advisory, Aviation Advisory, Risk Advisory, and Sustainability Advisory for clients across regulated financial services, aviation, fintech, eGaming, technology, and construction sectors.

Quantifiable outcome

• Global reach across 149+ countries through international network
• +2 more outcomes

Named customers6 records

Segments6 records

Ideal customer profiles5 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

One partnership is on record.

• Grant Thornton International Ltd (GTIL)coreOthersGrant Thornton Isle of Man is a member firm of Grant Thornton International Ltd, a global organization of member firms providing assurance, tax and advisory services in over 149 countries with 73,000 people. GTIL is a non-practicing, international umbrella entity incorporated in England and Wales.

Scale indicators7 records

Recent moves8 records

Expansion highlights6 records

Direct peers

• Deloitte Isle of Man: Deloitte IoM serves funds, corporates, and public sector clients with audit, tax, and consulting — a Big 4 direct competitor within the same IoM regulated services ecosystem.
• Crowe Isle of Man: Crowe IoM provides audit, tax, and advisory services to IoM financial services and corporate clients, representing another mid-tier direct competitor in the same local professional services market.
• PwC Isle of Man: PwC IoM provides assurance, tax, and advisory to IoM funds, insurance, and trust clients, representing the fourth Big 4 peer competing directly for IoM regulated-services mandates.
• KPMG Isle of Man: KPMG's Isle of Man practice provides audit, tax, and advisory to funds, insurance, and fiduciary clients in the IoM — directly competing with Grant Thornton IoM for the same regulated financial services client base.
• RSM Isle of Man: RSM IoM provides audit, tax, and consulting to IoM-based mid-market clients in financial services and corporate sectors, directly competing with Grant Thornton IoM in the same local market.
• BDO Isle of Man: BDO IoM is a mid-tier accounting and advisory firm serving IoM corporates, funds, and family offices — a direct peer at the same tier as Grant Thornton IoM with comparable service lines.
• EY Isle of Man: EY's Isle of Man office offers assurance, tax, and advisory services to IoM-domiciled funds, insurance, and corporate clients, competing head-to-head for the same mid-market and large enterprise mandates.
• Baker Tilly Isle of Man: Baker Tilly IoM is a mid-tier professional services firm offering audit, tax, and advisory to IoM corporates, funds, and fiduciaries — directly comparable in scale and service mix.

Broad incumbents

• Grant Thornton Ireland: Grant Thornton Ireland is the parent platform of which Grant Thornton IoM is a member, operating across Dublin, Belfast, Cork, Galway, and Limerick with ~3,000 people — broader scope but identical brand, services, and partner pool.

Emerging players

• Moore Stephens (now Moore) Isle of Man: Moore IoM provides audit, accounting, and advisory services to IoM corporates and fiduciaries through an international mid-tier network — a comparable mid-tier peer targeting overlapping mid-market client segments.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks5 records

Key highlights6 records

Customer concentration

• LinkedInlinkedin.com/company/grant-thornton-isle-of-man

Revenue estimate

Valuation estimate

Number of profiles

Profiles6 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Grant Thornton Isle of Man