Nearest rival PwC also reported strong growth in fee income to $41.28bn (£31.94bn), but at 10% this was not good enough to narrow the gap, which now stands at nearly $1.92bn (2017 $1.2bn).
This is despite the fact that PwC is the firm with the largest fee income in all the world’s regions except North America – where Deloitte retains poll position.
The world rankings, published annually by International Accounting Bulletin (IAB), also reveal that both Deloitte and PwC are drawing away from the rest of the pack, including fellow Big Four firms, EY and KPMG. The gap between PwC and EY has now widened to $6.5bn, up from $6.2bn, with KPMG tagging along some $5.81bn behind EY and $14.3bn behind Deloitte.
All the Big Four reported revenue in double digits. EY’s rose 11% to $34.77bn (£26.9bn) while KPMG’s increased by 10% to $28.96bn (£22.43bn). They also took on more staff and each now employs more than 200,000 people around the world. Deloitte leads with a workforce of 286,000 (up 8%).
To bridge the ever-widening gap between KPMG, the smallest of the Big Four, and the “challenger firms”, the next five largest – BDO, Grant Thornton, RSM, Crowe and Nexia International – would have to merge with each other.
At number five, BDO saw fee income rise 11% to $8.99bn (£6.96bn), while Grant Thornton knocked RSM into seventh place with a 9% rise in revenue to $5.44bn (£4.21bn). RSM achieved a 5% rise to $5.37bn (£4.15bn).
Star performer among the top 10, though, was eighth-placed Crowe, which saw its 2018 revenue rise 14% to $4.33bn (£3.35bn) on the back of a strong result from the audit business – up 24% to $2.08bn.
Ninth and 10th placed Nexia International and Baker Tilly International reported results up 10% to $4bn (£3.09bn) and 7% to $3.63bn (£2.81bn) respectively.
However, Crowe’s sparkling performance was put into the shade by ShineWing International, in 20th place, which saw its fee income rise overall by 26% to $454.8m. The network also increased its staff numbers by 22% to 8,258, the largest rise of all 31 networks in the IAB listing.
Altogether, the 31 networks contributed $196.05bn (£151.35bn) to the global economy.
IAB has also published its annual listing for international associations of accountancy firms. By far the largest is Praxity which, with its turnover of $5.83bn (£4.5bn), dwarfs next place LEA Global/Leading Edge Alliance by some $2.52bn.
Third place is taken by Allinial Global with fee income of $3.02 (£2.33bn), followed by GGI with $2.7bn (£2.08bn) and PrimeGlobal with $2.5bn (£1.93bn).
The average growth for the 21 networks was 6% although there were several with very impressive results. GMN International for example, posted fee income up 57%, thanks to the addition of five new member firms.