Carey Olsen has moved up nine places to secure the lead in the AIM Advisers Rankings Guide.
The April 2026 rankings put Carey Olsen in first place based on total AIM client market-capital.
Collas Crill was ranked joint fifth.
Commenting on the wider rankings, Adviser Rankings said: “These results suggest that while Law Firms to AIM-Listed companies are facing a tough and increasingly competitive market environment in which to win new clients, they are retaining clients better in Q1 this year as compared to the equivalent period last year.
“While the significant decrease in client losses will have been impacted by the fallout from Memery Crystal closing last year, a combination of factors have contributed to the trend. These could include client reticence to change Law Firm amidst the recent instabilities of the global environment, but also that Law Firms are building relationships, providing a service and managing fee rates in a way that increases retention.
“The ongoing factors of contraction and introspection faced by London’s enduring junior market, as well as the continued rise of challenger firms reshaping client expectations, talent acquisition, and operational models, is likely to drive further M&A. Law Firms will look to develop their offering and grow their market share through strategic acquisition as well as through organic development and by attracting new clients.
“The AIM Advisers Rankings Guide highlights those Law Firms that have clearly performed well in the rankings in Q1.”