Hargreaves Lansdown is one of only two companies in the FTSE 100 which has not located any of its subsidiaries in a tax haven.
According to a report by charity ActionAid, the FTSE 100 businesses have a combined total of 34,216 subsidiary companies, a quarter of which are in tax havens, including 600 in Jersey, 400 in the Cayman Islands and 300 in Luxembourg.
The 'big four' banks alone have 1,649 companies in tax havens, while the biggest tax haven user overall is advertising company WPP, with 611.
The only FTSE 100 businesses which do not have any subsidiaries in tax havens are Hargreaves Landsdown and gold and mining company Fresnillo.
Hargreaves spokesman Ben Yearsley said the report was "not particularly surprising" considering most of the FTSE 100 business had overseas operations.
"We are one of the few FTSE 100 companies which is completely UK-focused. All our clients are in the UK and we only sell in the UK," he said.
ActionAid said the use of tax havens is undermining the revenue bases of both developing and developed countries and has urged the government to rethink its current proposals to relax UK anti tax haven rules.
Chris Jordan, the charity's tax justice expert, added: "Tax havens have a damaging impact on the UK exchequer, the stability of the international financial system, and vitally on the ability of developing countries to raise tax revenues which would lift them out of poverty and make them less dependent on aid."
Two global vehicles
'Further plug advice gap'
Must appoint separate CEOs and boards
Advisers do come out well
Will report to Mark Till