KPMG became the largest auditor of FTSE 100 companies-judged by number of clients in Q4 – after it gained a single client in the period.

The extra client gave KPMG 28 clients, compared to PWC’s 27. PwC’s number was unchanged compared to the prior quarter.

This marked the first time since 2005 that PwC was not top of the pile when it came to number of FTSE 100 clients.

Deloitte, which also had 27 clients in Q3, came in third with a total of 26 top-tier constituents, after losing Sky.

EY rounded out the Big Four with 17 clients.

In total, the Big Four audited 98 of the FTSE 100, with the exception of one audit client for Grant Thornton and one for BDO.

By market cap PwC remained first by some way. The market cap of its FTSE 100 clients was £560,784m, comfortably ahead of Deloitte (just under £480,000m) in second.

Dropping down to the FTSE 250, PWC grew its lead slightly, with 74 clients, compared to second placed KPMG’s 63. Deloitte and EY were third and fourth with 58 and 45 respectively.

Grant Thornton and BDO were again the only non-Big Four representatives with clients. Grant Thornton had six, and BDO four. 

AIM client rankings showed BDO taking first place with 149 clients for November 2018, an increase compared to 145 in Q3 2018.

KPMG took second place for AIM client rankings with 123 clients in November 2018. This was a decrease compared to 130 in August 2018.

Grant Thornton, PwC, and Deloitte follow in third, fourth and fifth place.

BDO is expected to grow its lead in the AIM market, after it revealed advanced talks were in place for a merger with Moore Stephens LLP. Moore Stephens UK (of which Moore Stephens LLP is a member) audited 24 AIM companies.

Total figures

Looking at total stock market clients, KPMG had the largest amount of clients with a total of 370, despite a decrease since August 2018, where it took 382 clients.

Following KPMG, PwC took second place with an increase of clients with 360, compared to August 2018 where it had 358 clients.

Respectively Deloitte, BDO and EY took third, fourth and fifth place.