The United Kingdom is the world’s sixth-largest economy with 5.6 million registered businesses.
It’s a truly dynamic market where every business, from small startups to large multinational corporations, requires accounting support to manage finances and tax regulations. That’s why the accounting industry revenue has grown steadily over the past five years, with a projection to reach almost £40 billion by 2025.
However, the market share is not distributed equally among all firms — some dominate the industry in terms of size and revenue.
In this post, we’ll present you with the 10 biggest accounting companies in the UK.
1. PwC
- Revenue: £5.79 billion
- Number of employees: 25,000+
- Number of partners: 1,057
PwC (PricewaterhouseCoopers) is not just the largest accounting company in the UK but also the second-largest in the world. The firm offers a massive portfolio of services including (but not limited to) audit and assurance, consulting, tax advisory, and financial advisory.
| Fun fact: PwC firms provided services to 87% of the Global Fortune 500 companies in 2023. |
PwC's UK operations are part of the company’s global network operating in over 150 countries. The company has over 25,000 employees working across 19 offices in the country. With such manpower, PwC easily serves both large multinational corporations and smaller businesses across all sectors.
Related: Top 10 accounting firms in the world
2. Deloitte
- Revenue: £5.6 billion
- Number of employees: 26,500
- Number of partners: 1,369
Although it employs more people, Deloitte claims the second spot on our list due to a somewhat smaller annual revenue (£5.6 billion). Deloitte UK is famous for its strong focus on innovation — it mainly invests in digital transformation, cybersecurity, and sustainability.
| Fun fact: Deloitte’s global CSR contributions exceeded $130 million in volunteer and pro bono work value. |
More importantly, the firm has made major investments in technology and data analytics to improve its service offerings. The company currently has more than 26 thousand employees across 19 offices all over the country.
3. EY
- Revenue: £3.76 billion
- Number of employees: 21,000
- Number of partners: 1,683
Number three goes to Ernst & Young, a prominent player in the UK’s professional services sector. This accounting firm has thousands of employees across 21 offices in the UK. EY is known for its focus on financial services, energy, technology, and consumer products.
| Fun fact: EY ranked top 10 among business students in the 2022 World’s Most Attractive Employers ranking. |
The firm has been at the forefront of digital transformation by offering data analytics, AI-driven solutions, and blockchain technology services. EY is also deeply invested in sustainability — it guides clients on environmental, social, and governance (ESG) practices to help them integrate sustainable strategies into their operations.
4. KPMG
- Revenue: £2.96 billion
- Number of employees: 18,000
- Number of partners: 826
Another “Big Four” company is on the list — the UK branch of KPMG is the fourth latest accounting and auditing practice in the country. KPMG has been growing recently: It recorded a 9% revenue growth in 2023 and hired additional staff (18,000 workers total).
| Fun fact: KPMG strongly supports golf and serves as the title sponsor of the KPMG Women’s PGA Championship. |
KPMG stands out for its commitment to ethical practices and corporate governance. It often advises clients on risk management, regulatory compliance, and responsible business conduct. The firm is also a leader in promoting diversity and inclusion within the workplace as it implements initiatives that support underrepresented groups.
Related: Ten of the top audit firms in the world in 2024
5. BDO
- Revenue: £935 million
- Number of employees: 7,500
- Number of partners: 441
Revenue figures drop below billion as soon as we leave the “Big Four” territory. BDO is the fifth biggest accounting company in the country with a £935 million revenue. It has a reputation for being a client-centric company that builds strong relationships through personalized communications.
| Fun fact: BDO designed a 5+5 citizenship program. The program encourages employees to spend 10 days a year helping other people or participating in CSR campaigns. |
With over 7,000 employees across 18 offices in the UK, BDO mainly serves medium-sized businesses, family-owned enterprises, and entrepreneurial ventures (though it also works with larger corporations and public sector organizations). The firm offers a full spectrum of services, including audit, tax, advisory, and business outsourcing.
6. Grant Thornton
- Revenue: £654 million
- Number of employees: 5,300
- Number of partners: 220
Grant Thornton is one of Britain’s leading professional services companies with 24 offices and more than 5,300 employees. This firm frequently works with dynamic organizations such as mid-market companies and fast-growing startups to provide expertise in audit, tax, and advisory services.
| Fun fact: According to the Working Families report, Grant Thornton is one of the top family-friendly companies in the UK. |
Grant Thornton has a notable presence in sectors such as financial services, healthcare, technology, and not-for-profits. In addition, it provides forensic and investigation services to help clients resolve financial disputes.
Related: Top accounting conferences for 2024
7. Evelyn Partners
- Revenue: £600.8 million
- Number of employees: 3,900
- Number of partners: 430
Evelyn Partners is a unique player in the British financial services landscape because it specializes in providing tailored financial solutions for individuals, families, and business owners. This includes services such as wealth preservation, investment management, tax planning, and estate management.
| Fun fact: Evelyn Partners excels at organizing relevant industry events — tax update seminars, investment webinars, charity conferences, and so on. |
In addition, the company has a broad scope of charity-focused financial services. For example, Evelyn Partners helps hundreds of nonprofits, charities, and philanthropic organizations with investment management, tax regulations, mergers, and cross-border projects.
8. RSM
- Revenue: £486.3 million
- Number of employees: 4,359
- Number of partners: 356
RSM mainly targets the middle market, with particular expertise in consumer markets and family businesses. With over 4,000 employees across 30 offices in the country, RSM offers a whole range of services including audit, tax services, risk advisory, and financial management.
| Fun fact: RSM was named the UK’s 5th best accountancy firm to work for in 2023. |
This firm’s financial experts also specialize in consumer-driven businesses such as retail and hospitality. RSM’s commitment to family businesses is another key differentiator. It assists family-owned enterprises with everything from succession planning and governance to tax structuring and wealth management.
Related: 15 accounting influencers you should follow
9. Azets
- Revenue: £361.6 million
- Number of employees: 3,800
- Number of partners: 379
Azets is the ninth-largest accounting firm in the UK, and it mostly works with small to medium-sized enterprises (SMEs) and local businesses. According to the firm’s website, Azets currently cooperates with more than 80,000 clients in the fields of online accounting, tax, audit, payroll processing, and financial analysis.
| Fun fact: Azets runs as many as 75 offices in the UK. |
Most clients praise the firm for its commitment to providing hands-on support that combines local expertise with the resources of a larger network. This is particularly useful for early-stage growth companies eager to properly scale their organizations.
10. Mazars
- Revenue: £335 million
- Number of employees: 3,200
- Number of partners: 171
Mazars provides an all-encompassing portfolio of services (accounting, tax, audit, advisory) for clients in dozens of industries. Their expertise is critical for organizations in specific fields such as life sciences and healthcare. In this case, Mazars relies on its deep sector knowledge to help guide clients through regulatory complexities.
| Fun fact: Mazars has independent non-executives serving on the Public Interest Committee. |
The firm is also recognized for its outsourcing capabilities. Mazar helps companies optimize their operations and reduce finance and payroll-related costs, allowing clients to focus on their core activities instead of financial processes.
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