Jillian O'Sullivan

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Advisory

Our progressive thinkers offer services to help create, protect and transform value today, so you have opportunity to thrive tomorrow.

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Aviation Advisory
Our dedicated Aviation Advisory team bring best-in-class expertise across modelling, lease management, financial accounting and transaction execution as well as technical services completed by certified engineers.
Business Risk Services
Our Business Risk Services team deliver practical and pragmatic solutions that support clients in growing and protecting the inherent value of their businesses.
Consulting
Our Consulting team guarantees quick turnarounds and superior results delivered on a range of services.
Deal Advisory
Our experienced Deal Advisory team has provided a range of transaction, valuation, deal advisory and restructuring services to clients for the past two decades.
Financial Accounting and Advisory
Our FAAS team designs and implements creative solutions for organisations expanding into new markets or undertaking functional financial transformations.
Forensic Accounting
Our Forensic and Investigation Services team have targeted solutions to solve difficult challenges - making the difference between finding the truth or being left in the dark.
Restructuring
Grant Thornton is Ireland’s leading provider of insolvency and corporate recovery solutions.
Risk Advisory
Our Risk Advisory team delivers innovative solutions and strategic insights for the Financial Services sector, addressing disruptive forces, regulatory changes, and emerging trends to enhance risk management and foster competitive advantage.
Sustainability Advisory
Our Sustainability Advisory team works with clients to accelerate their sustainability journey through innovative and pragmatic solutions.

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Article 2025 Reinsurance Renewal Insights: Key Matters to Consider

2025 reinsurance renewal: Key trends in property, casualty, and cyber markets. Gain insights on rates, catastrophe losses, and the insurance protection gap.

| 5 min read | 15 Nov 2024

Audit

Our audit services can strengthen your business and stakeholders' confidence. You'll receive professionally verified results and insights that help you grow.

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Corporate Accounting and Outsourcing
At Grant Thornton we have extensive knowledge and experience in providing tailored solutions to our clients, whether on a short-term or long-term basis.
Financial Services Audit
Our Financial Services Audit team offers expertise and knowledge along with a horizontal approach to solving clients’ problems and queries.
Global Statutory Audit
Our Global Statutory Audit team ensures your statutory audit process follows a well-defined project plan, with no surprises, to maintain compliance across multiple jurisdictions. We invest time to understand your finance function and develop bespoke solutions built on the premise of central effort to remove duplication.
Pension Audit
The Grant Thornton Pension Audit team has vast experience in managing schemes and preparing annual reports on them for clients.

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Article The latest updates on Companies House reform

Discover key updates on UK Companies House reform, including mandatory ID verification, software-only filing, and revised company size thresholds.

| 4 min read | 13 Nov 2024

Tax

Our tax services help you gain trust and stay ahead, enabling you to manage your tax transparently and ethically.

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Corporate Tax
Our Corporate Tax team is made up of more than 40 highly experienced senior partners and directors who work directly with a wide range of domestic and international clients; covering Corporation Tax, Company Secretarial, Employer Solutions, Global Mobility and Tax Incentives.
Financial Services Tax
The Grant Thornton team is made up of experts who are fully up to date in terms of changing and evolving tax legislation. This is combined with industry expertise and an in-depth knowledge of the evolving financial services regulatory landscape.
Indirect Tax Advisory & Compliance
Grant Thornton’s team of indirect tax specialists helps a range of clients across a variety of sectors including pharmaceuticals, financial services, construction and property and food to navigate these complexities.
International Tax
We develop close relationships with clients in order to gain a deep understanding of their businesses to ensure they make the right operational decisions. The wrong decision on how a company sells into a new market or establishes a new subsidiary can have major tax implications.
Private Client
Grant Thornton’s Private Client Services team can advise you on all areas of financial, pension, investment, succession and inheritance planning. We understand that each individual’s circumstances are different to the next and we tailor our services to suit your specific needs.

Related insights:

Article Simplifying Group Structures: Group Rationalisation

Managing compliance across companies is time-consuming and often overlooked. Eliminating dormant companies reduces administrative and audit costs, freeing up finance directors.

Jillian O'Sullivan

| 7 min read | 20 Nov 2024

Careers

Looking for a more fulfilling role in professional services? Find out more about our opportunities.

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Experienced Hires

Looking for a more fulfilling role in professional services? One where fresh thinking, collaboration and diversity are valued? At Grant Thornton we do things...

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Graduate Programme

We offer a range of graduate programmes to help you thrive in your career. Work with and learn from the best in the business, make a difference and excel by...

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Undergrad Programme

We offer a fantastic opportunity to kick-start your career with our Summer Internship Programme.

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Working at Grant Thornton

We’re committed to our culture, our clients and the better future that we can build together.

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Our Benefits

We offer an excellent range of rewards and benefits to suit your lifestyle.

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Connect

About us

Grant Thornton Ireland is rapidly approaching 3,000 people, in 9 offices across Ireland, Isle of Man, Gibraltar and Bermuda, and a presence in over 149...

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Alumni network

We believe in a connected world — so we created an industry-leading online Alumni Network that focuses on what matters most at Grant Thornton — our people.

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Events

Browse our schedule of upcoming live events or webinars for the latest thinking from Grant Thornton's subject matter experts.

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News centre

Explore Grant Thornton's latest press releases and stay informed with our most recent news updates.

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Subscriptions

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Experience

Jillian leads our company secretarial and employer solutions team which includes the provision of outsourced payroll services.

She assists companies establishing a presence in Ireland, from their initial setup to their on-going compliance, payroll and other outsourced service requirements. She also deals with all areas of corporate compliance and governance.

Jillian has significant experience in the restructuring of corporate entities and groups, both medium and large, and in the implementation of related tax planning and succession schemes.

She lectures extensively and facilitates seminars on both the role and responsibilities of directors in companies.

Qualifications

Fellow of the Chartered Governance Institute UK and Ireland
Current President of the Institute in Ireland
Chairs the company secretarial practice committee and is a member of the Governance and Nomination Committee
Diplomas in Commercial Law and Corporate Governance from the Law Society of Ireland
Diploma in Taxation from the Irish Institute of Tax

Latest Articles

Article Simplifying Group Structures: Group Rationalisation

Managing compliance across companies is time-consuming and often overlooked. Eliminating dormant companies reduces administrative and audit costs, freeing up finance directors.

Jillian O'Sullivan

| 7 min read | 20 Nov 2024