Cusack & Co

What Cusack & Co does

Cusack & Co is a privately held Irish accountancy and advisory firm headquartered in Mount Merrion, Dublin, founded in 1991 by Cathal Cusack. The firm provides a full suite of traditional professional services including statutory audit (Registered Auditors), Chartered Tax Advice covering income tax, corporation tax, VAT, CGT, and CAT, and Business Advisory for owner-managed businesses, senior executives, private clients, and international organisations. It also operates a specialist Revenue Audits & Investigations practice with representation at Tax Appeal Commission and High Court level, anchored by its role as lead adviser in the precedential Deane v Revenue Commissioners [2018] IEHC 519 case. The firm serves clients in Ireland, the UK, and internationally, with cross-border work delivered through its membership in MSI International Global Alliance.

The underlying technology footprint is that of a traditional professional services firm: no proprietary software, no API, no SaaS or mobile application, and no disclosed automation or AI tooling. All services are delivered through direct client engagement via phone, email, in-person consultation by appointment, and a downloadable 'Doing Business in Ireland' guide on the firm's website. Inputs are people-intensive: chartered accountants (ACCA, CTA, CIMA qualified), audit and accounts directors, and practice management staff. Distribution is partner-mediated internationally through MSI's 250+ member firms across 100+ countries and direct in the Irish market.

The revenue model is professional services fees, billed on a quote-based, scope-determined basis for advisory, audit, and compliance engagements. The firm sells no products, owns no patents, and has no funding rounds. Its competitive positioning is relationship-driven: a single senior point of contact per client, technical expertise comparable to larger international firms, and a personal partnership approach that explicitly positions against large impersonal firms. There is no public listing, no external investors, and no disclosed financial figures.

Name

Cusack & Co

Legal name

Cusack & Co

Website

https://cusackco.ie

Company type

Private

Founded year

1991

Operating status

Operating

Headcount range

1–10 employees

Short description

Cusack & Co is a Dublin-based, privately held accountancy and advisory firm founded in 1991 providing statutory audit, Chartered Tax Advice, Business Advisory, and Revenue investigation support to owner-managed businesses, senior executives, private clients, and international organisations, with cross-border reach via MSI International.

Ownership category

akta.pro rank

Headquarters

HQ city

Mount Merrion, Co Dublin

HQ country

Ireland

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B and B2C

Offering type

Services

Cost components

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

Revenue model

1. Professional Accounting Services: Full-service accountancy firm providing Registered Auditors, Chartered Tax Advice, and Business Advisory services. Revenue generated through professional service fees, likely billed on hourly or fixed-fee basis for advisory, audit, and compliance services.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels5 records

Core offering

Cusack & Co is a Dublin-based accountancy firm providing statutory audit, chartered tax advice, business advisory, and international advisory services to owner-managed businesses, private clients, and international organisations. Its services include Revenue audit defence and representation at Tax Appeal Commission and High Court level, alongside cross-border tax compliance through MSI International membership.

Product overview

Cusack & Co is a traditional full-service accountancy firm offering a unified suite of professional services rather than a software product. The core offerings consist of Registered Auditors (statutory audit services), Chartered Tax Advice (tax advisory and planning), Business Advice (growth and structuring guidance), and International Advisory (cross-border compliance). Revenue Audits & Investigations functions as a specialized service module within the tax practice. The firm does not offer a SaaS platform, software product, or API-based solutions.

Differentiator

Problem solved

Functional benefit

Quantifiable outcome

• Completed statutory audit and corporation tax returns within 2 weeks for M&A due diligence process
• +2 more outcomes

Named customers4 records

Segments10 records

Ideal customer profiles4 records

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Partnerships

One partnership is on record.

• MSI International Global AlliancecoreStrategic or Co-development PartnerCusack & Co is MSI International's appointed accounting member for the Republic of Ireland. This membership provides clients access to over 250 independent legal and accounting firms in more than 100 countries worldwide. The alliance enables the firm to offer integrated, multidisciplinary services for international clients and connect Irish clients with trusted advisors globally.

Scale indicators3 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Crowe Ireland: Irish member of the Crowe Global accounting network, providing audit, tax, and advisory services to SMEs, owner-managed businesses, and international groups entering Ireland.
• EisnerAmper Ireland: International accounting and advisory firm with an Irish presence serving SMEs, owner-managed businesses, and international clients with cross-border tax and audit needs.
• Mazars Ireland: Mid-tier international accounting and advisory firm operating in Dublin. Directly comparable as a similarly positioned alternative to Big 4 serving owner-managed businesses and international clients in Ireland.
• HLB Ireland: Irish member of the HLB international accounting network offering audit, tax, and advisory services to owner-managed and cross-border clients — comparable alternative mid-tier firm.
• PKF Ireland: Irish member of the PKF international accounting network, providing audit, tax, and advisory services with comparable mid-market and international client base.
• Baker Tilly Ireland: Irish member of the Baker Tilly international network providing accounting, tax, and advisory services to SMEs and international groups with Irish operations.
• BDO Ireland: Mid-tier international accounting network in Ireland offering audit, tax, and advisory services to owner-managed businesses, regulated entities, and international corporates — direct competitor in Cusack & Co's core segments.
• Grant Thornton Ireland: Mid-tier international accounting and advisory firm with strong Irish presence, serving owner-managed businesses and international clients. Directly comparable mid-market positioning.
• Russell Brennan Keane: Irish mid-tier chartered accountancy firm offering audit, tax, and advisory services to SMEs, owner-managed businesses, and not-for-profits — directly comparable in scale and segment focus.

Broad incumbents

• Deloitte Ireland: Big 4 firm operating in Ireland across audit, tax, and advisory. Represents the larger incumbent competitor that Cusack & Co explicitly positions against for owner-managed and international clients.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks5 records

Key highlights6 records

Customer concentration

• LinkedInlinkedin.com/company/cusackco

Revenue estimate

Valuation estimate

Number of profiles

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 Cusack & Co