So much money is flowing into tax shelters that companies may have booked more profits in Bermuda than in China, the second-largest economy in the world.

The United Nations found that multinational firms from a sample of 26 developed economies reported more profit from holding companies in the tiny island of Bermuda ($43.7 billion) than in China ($36.4 billion). There’s also been a greater move toward the use of foreign holding companies.

“The proportion of investment income booked in low tax, often offshore, jurisdictions is high — and possibly growing,” the report said.

Companies around the world poured $221 billion into tax havens in 2015, with a greater portion of the money coming from China, Russia and Brazil, according to the report. Luxembourg, the Netherlands, the Cayman Islands and the British Virgin Islands were among the biggest destinations for companies seeking tax shelters.

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The U.N. has been calling for more cooperation among countries on tax laws as a way to combat the use of tax havens. The euro zone recently tightened laws among member countries, and it may have caused multinational companies to pull money out of Luxembourg and Netherlands in the final three months of 2015.

“The persistence of financial flows routed through offshore financial mechanisms highlights the pressing need to create greater coherence among tax and investment policies at the global level,” the U.N. report said.

Yet the kind of far-reaching tax coordination long urged by the U.N. is unlikely given the benefits that accrue to some countries because of lower tax rates, a key component of attracting or retaining business.

Competition among countries on taxes can also have salutary effects, such as making sure taxes don’t get too high and choke off economic growth. Even in the U.S., the Obama White House has at least given public lip service to the idea that the corporate tax code is outdated and uncompetitive.

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Still, there’s no doubt countries lose billions in potential tax revenue because of widespread use of tax shelters as a matter of course. Tens of billions of dollars were poured into these tax havens in the first three quarters of 2015, triple the amount of the year before. Another annual record might have been set if not for large withdrawals in the last three months of the year.

The reason: many multinational firms used the withdrawn cash to pay off loans that part of a corporation in one country gave to another unit in a different country, the U.N. suggested. These cross-border loans are often structured to minimize taxes.

New investment in offshore tax havens in the Caribbean — namely the Cayman and Virgin Islands — fell again in 2015 to $75 billion. That’s down 42% from three years ago, but excluding a surprising surge in 2013, it’s in line with annual average over the past decade.

In 2013, inflows into these tax-sheltering islands set a record $132 billion, as companies moved cash around to fund a wave of large cross-border mergers and acquisitions.

Although the Caribbean has benefited heavily in the past from U.S. money, more cash is now coming from China, Russia and Brazil. The trio accounted for 65% of the investment flows to the Cayman and Virgin Islands last year. About 21% came from the United States.