Do you mean worldwide or within the UK? I’ll assume you want the largest accounting networks globally. Below is a commonly used “Top 10” by recent reported network revenue (latest published fiscal-year figures available, 2024–2025).

Top 10 accounting firms (global networks) — approximate revenue and source

1. Deloitte — ≈ $66–67 billion. (Statista.com)
2. PwC (PricewaterhouseCoopers) — ≈ $53–55 billion. (Statista.com)
3. EY (Ernst & Young) — ≈ $49–51 billion. (Statista.com)
4. KPMG — ≈ $36–38 billion. (Statista.com)
5. BDO — ≈ $13–14 billion. (big4accountingfirms.com)
6. RSM — ≈ $8–10 billion. (big4accountingfirms.com)
7. Grant Thornton (network) — ≈ $6–8 billion. (big4accountingfirms.com)
8. Nexia / Forvis / Crowe / Baker Tilly area (mid-tier networks) — each typically in the ~$4–6 billion range (these four often appear in 8–11 positions depending on the year). (big4accountingfirms.com)
9. Crowe — ≈ $4–6 billion. (big4accountingfirms.com)
10. Baker Tilly / Mazars / Forvis / Nexia (depending on the metric/year) — ≈ $4–6 billion. (big4accountingfirms.com)

Notes and caveats

• “Accounting firms” here means global networks (member firms operating under a network brand). Rankings use network-wide revenues published for fiscal years 2023–2024 or 2024–2025; different sources report slightly different figures and cutoffs, so exact 5–10 positions among the mid-tier networks can vary between lists. (Statista.com)
• The “Big Four” (Deloitte, PwC, EY, KPMG) consistently occupy the top four places by a large margin. (Statista.com)
• If you want a precise, dated ranking (for example “top 10 by revenue for fiscal year 2024” or “top 10 firms in the UK”), tell me which year or region and I’ll pull the exact published figures and sources.