Britain and the Netherlands are two of the biggest channels for tax avoidance, with almost 40% of corporate investments hidden from the authorities travelling through the two countries on their way to a tax haven.
According to a study carried out by a team of researchers at the University of Amsterdam, which has analysed the ownership structure of 98 million firms, 37% of investments kept away from the tax man are channeled through the UK and the Netherlands.
Some 23% of investments that ended in a tax haven were funneled through the latter, while the UK accounted for 17%, ahead of Switzerland, Singapore and Ireland with 6%, 2% and 1% respectively.
Most of the investments directed through the UK end up in former Commonwealth countries, such as the Channel Islands and Bermuda. The Netherlands, meanwhile, acts as a channel for funds that tend to end up in Switzerland or Cyprus. Ireland is the preferred route for US and Japanese companies aiming to deposit funds in Luxembourg.
"Our results show that offshore finance is not the exclusive business of exotic small islands far away," the researchers wrote in an article published in the academic journal Scientific Reports.
"Countries such as the Netherlands and the United Kingdom play a crucial yet previously hidden role as conduits of offshore finance on its way to tax havens."
The European Union misses out on up to £158bn ($205.7bn) in taxes, due to multinationals channeling funds to tax havens, while the figure drops to £99bn in the US.
The report added foreign capital was almost always stored in 24 offshore tax havens, 18 of which such as the Cayman Islands, Bermuda, the British Virgin Islands and Jersey, have or once had dependence to the UK.
"In the context of Brexit, where you have the UK threatening, unless they get a deal, to change their model to be attractive to companies who want to protect themselves from taxes, well, they are already doing it," said Dr Eelke Heemskerk, who led the research.
"The Netherlands says they won't let the UK be an offshore tax haven. That's because they don't want them taking their business."