Chartered Certified Accountants in East Sussex

Independent accountancy, tax and advisory for owner-managed businesses. Based in East Sussex, working with clients across the UK.

Book a Discovery CallSpeak to an Advisor

About MSU Advisory

Experience You Can Trust. Advice You Can Act On.

MSU Advisory Limited is an independent firm of Chartered Certified Accountants based in East Sussex, providing accountancy, taxation and strategic business advisory services to owner-managed businesses, entrepreneurs, family companies and private clients.

Founded by Mark Underdown FCCA, the firm is built upon more than 20 years of professional practice experience and over a decade of leadership as a director within a well-established chartered accountancy firm.

We believe that modern accountancy should go beyond preparing accounts and filing tax returns. Our role is to help clients understand their numbers, plan ahead, manage risk and make better-informed decisions. Whether you need reliable compliance support, proactive tax planning, outsourced finance director expertise or practical business advice, we provide guidance that is commercially relevant and easy to understand.

Our approach is built on long-term relationships. We take the time to understand your business, your ambitions and the challenges you face, so that our advice is tailored, timely and genuinely useful. By combining traditional professional standards with modern systems, cloud technology and automation, we help clients build stronger, more efficient and more resilient businesses.

About MSU Advisory

Why MSU Advisory

Why choose MSU Advisory?

Combining traditional professional values with modern technology, we deliver expert accounting, taxation and strategic business advice for ambitious business owners.

Independent and Client Focused

As an independent practice, we are able to provide advice that is personal, objective and tailored to your circumstances. We work closely with clients and aim to provide the continuity, accessibility and judgement that business owners value from a trusted advisor.

Experienced Strategic Advisors

With more than two decades of practice experience and senior leadership experience within a chartered accountancy environment, we bring both technical expertise and commercial perspective. Our advice is practical, proportionate and focused on helping you move your business forward.

Technology and AI Driven

We actively embrace cloud accounting, automation and AI-enabled tools where they can improve accuracy, efficiency and insight. Our aim is to reduce unnecessary administration, improve real-time visibility and give clients better information on which to base decisions.

Responsive and Accessible

Clients work directly with senior professionals who understand their business and provide timely support when it matters most.

Long-Term Partnerships

We aim to build lasting relationships and become a trusted part of your management team.

About our practice

What we do

Services overview

Compliance is in place. The work that sets us apart is helping you shape the business and take part in strategic decisions.

Business Accounting & Compliance

We help businesses meet their statutory and tax obligations with confidence. Our compliance services are designed to be accurate, efficient and well organised, giving you peace of mind that deadlines are met and your financial information is presented clearly.

Tax Planning & Advisory

Effective tax planning starts with understanding your wider personal and commercial objectives. We provide proactive advice to help structure affairs efficiently, manage risk and support long-term wealth creation and preservation.

Business Advisory Services

We work with business owners to improve performance, strengthen cash flow and make better strategic decisions. Our advisory services are designed to turn financial information into practical actions that support profitability, productivity and growth.

CFO & Finance Director Services

Growing businesses often need senior financial expertise before they are ready to appoint a full-time Finance Director or Chief Financial Officer. Our outsourced support provides flexible, board-level guidance to help you understand performance, plan for growth, manage cash flow and make informed strategic decisions.

Cloud Accounting, Automation & AI

Technology should make finance functions more efficient, more accurate and more useful to the business. We help clients implement and improve cloud accounting systems, automate routine processes and make better use of financial data through dashboards, reporting tools and AI-assisted workflows.

Signature service

The Business Owner Advisory Programme

Statutory accounts and tax compliance are certainly offered. The ideal engagement is an advisory relationship: helping to shape the business and taking part in strategic decision-making in a key senior financial role.

The Business Owner Advisory Programme is that marketed service — a structured relationship through the year, not a once-a-year filing exercise.

  • Quarterly strategy meetings
  • Management accounts review
  • Cash flow forecasting
  • Tax planning
  • Remuneration review
  • Annual wealth planning review
  • Direct access to advice

Book a Discovery Call