Britain kept the top spot in global financial services exports in 2016, but Brexit threatens to raise barriers to its biggest market in Europe, according to industry body TheCityUK.
Britain as a financial centre netted a total trade surplus of $93.6 billion in 2016, more than the next two leading countries – the United States and Switzerland – combined, TheCityUK said.
However, Anjalika Bardalai, TheCityUK's chief economist and head of research, warned that the position could not be taken for granted.
"Brexit is likely to create some economic friction with our largest trading partner - the EU and with an increasing number of regional and specialist centres arising in Asia and elsewhere - it is vital that the UK seek new trading and investment opportunities."
It also needs to step up trade with existing major partners like the United States and Japan, TheCityUK said.
"While markets like China and India are growing fast, trade flows are still relatively small, indicating potential for the future.”
Britain is sending a trade delegation to China this weekend that will include financial services firms such as the London Stock Exchange to drum up business to help plug any gap in business lost due to Brexit.