Financial Services Lawyers

We are a specialist financial services law firm based in London. We share the depth and breadth of decades of experience working with the full range of financial services firms from the largest banks and asset managers to smaller fintechs, payments, and crypto firms.

As financial services is all we do, it is important that we do it very well. All work is undertaken by a senior specialist lawyer – ensuring excellence, efficiency and responsiveness.

Firms We Work With

We have experience of providing legal and regulatory services to a wide range of firms in the financial services sector.

Digital Financial Services

Digital Financial Services

We are passionate about innovation in financial services and support many firms from household name trail blazers in payments, to smaller fintech start-ups.

Fund & Asset Management

Fund & Asset Management

We have extensive experience of advising on fund structuring and marketing; and compliance with AIF / CIS regimes. We act for a range of asset managers on regulatory compliance.

Banks & Building Societies

Banks & Building Societies

We work with many UK & overseas banks & building societies on treasury (incl. reg capital); transactional (incl. client and business transfers) and regulatory compliance matters.

Investment Firms

Investment Firms

We work with a diverse range of investment firms including equity / CFD brokers; wealth managers; IFAs; and commodity traders. We have a deep understanding of related regulation, in particular, MiFID2 and MIFIDPRU.



We have a range of experience in the insurance sector, including analysis as to whether arrangements constitute a contract of insurance; and product design and distribution arrangements.

Why Choose Our Law Firm?

As lawyers specialising solely in financial services, we provide:

A wealth of experience across financial services

A wealth of experience across
financial services

We draw on over 80 years of combined experience working with a wide range of financial services firms. This experience means that we can share practical solutions that we have seen work before as well as develop new legal approaches.

As financial services is all we do, it is important that we do it very well. We closely follow regulatory developments, sit on industry working groups, and are involved in responding to the FCA and the PRA on key regulatory consultation papers.

Your trusted financial services advisors

Trusted and accessible

We invest time to understand our clients' businesses, build lasting relationships and become trusted advisors.

It is also important to our clients that we are accessible – always available at the end of the phone - and that work is done by a specialist senior lawyer, not handed down to junior associates.

Interested and engaged in financial services

A different way
of charging

Unlike many law firms, we don’t just charge by the hour.

We provide you with a firm estimate of costs before work starts so there are no surprises.

Our clients tell us that we provide City law firm quality at the right price point.

Expert Financial Services Lawyers

We are a specialist team of expert financial services lawyers and advisors.

Brian McDonnell

Brian McDonnell


Brian is recognised for providing practical advice to a wide range of financial services firms. He has over 20 years of experience, 12 years as a city law firm partner most recently as head of Financial Markets at Addleshaw Goddard. He is ranked by both Chambers and Legal 500 as a leading individual (Financial Services: Non-contentious Regulatory).

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David Ellis

David Ellis


David has over 20 years of experience providing legal services to financial services firms. He has in-depth industry knowledge having worked for a period in-house (at Citigroup and Legg Mason) with a particular focus on asset management.

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Paul Estlin

Paul Estlin


Paul is a financial services regulatory lawyer with over 20 years’ experience. He has a wealth of experience, combining a deep understanding and technical knowledge with a practical approach. He worked as a regulator at the Financial Services Authority and one of its predecessors, the Personal Investment Authority.

Simon Williams

Simon Williams


Simon is a highly experienced financial services regulatory and commercial lawyer specialising in the insurance sector, with over 25 years experience. He was previously General Counsel for a major insurance firm and before that a Chambers ranked City law firm partner. Simon is a business-focused lawyer with a proven track record of solving complex issues.



View our latest law firm news and insights.

Regulatory Winter for UK Financial Promotions from 2024

A confluence of recent and upcoming changes in regulation represent a step-change in the UK environment for the communication financial promotions (broadly, the marketing of financial services and products). Against the backdrop of strengthened rules for firms communicating or approving financial promotions for “high-risk investments”, in force from 1 February 2023, three recent and upcoming […]

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Financial Services Lawyers FAQS

Listed below are some common questions and answers about our firm.

If you cannot find an answer to your question, then book a free consultation today.

What types of business do you work with?

We specialise in legal and regulatory services to financial services businesses, including:

  • Banks / Building societies
  • Fund & Asset managers
  • Wealth managers
  • Investment firms
  • Brokers
  • Pension providers
  • Insurers
  • Fintechs
  • Crypto providers

We advise on the full range of regulatory and commercial legal matters affecting financial services businesses. For example, our work includes:

  • how to interpret and apply FCA and PRA regulation;
  • how to implement new law and regulation affecting financial services businesses;
  • advising on new business models including crypto projects;
  • advising payments / e-money firms;
  • designing and drafting regulatory capital instruments;
  • fund structuring and drafting fund documentation;
  • drafting agreements for financial services businesses including: customer Ts&Cs; outsourcing agreements; investment management agreements; and AIFM agreements; and
  • due diligence of financial services businesses.

We also provide wider regulatory services including FCA / PRA authorisation applications; crypto-exchange registrations; drafting compliance documents / manuals; and regulatory consulting.

Can you help determine whether my business needs to be authorised?

Yes, we work with many businesses who seek advice on whether they require authorisation by the FCA or the PRA. We can often help firms identify exemptions from the need for authorisation or provide advice on how they can change their business model to avoid the need for authorisation. We also advise on whether arrangements may constitute a Collective Investment Scheme (and/or an Alternative Investment Fund) which would require an FCA authorised operator (and/or AIFM).

Can you help get my business authorised by the FCA?

Yes, we can help you apply for FCA or PRA authorisation and/or to register your crypto-exchange with the FCA.

Can you work with other law firms?

As the UK’s only specialist financial services regulatory law firm, we collaborate with many law firms which don’t have our specialist regulatory capability (or don’t have sufficient capability). We help such law firms provide legal services to their clients or support on the regulatory elements of corporate / funds transactions.

How long has your law firm been established?

McDonnell Ellis LLP was established in May 2020 by two experienced financial services partners who left City law firm Addleshaw Goddard LLP. It now has three partners, all specialists in financial services law and regulation.

How do you charge?

Unlike many law firms, we don’t just charge by the hour. We provide you with a firm estimate of costs before work starts so there are no surprises. Our clients tell us that we provide City law firm quality at the right price point.

Where is your law firm based?

We are based in London, United Kingdom – 86-90 Paul Street, London, EC2A 4NE.

Do you have offices outside the UK?

No, but we have an international network of the some of the best financial services lawyers and regulatory specialists. Unlike international firms which are restricted to using their local office, we can choose to work with the best lawyer / specialist in a foreign jurisdiction.

Are you registered with the Solicitors Regulation Authority?

Yes, we are registered with the Solicitors Regulation Authority. You can view our registration profile here.