Tax authorities routinely exchange data about financial accounts and investment portfolios through the OECD Common Reporting Standard. Since 2017, dozens of countries have used these transparency rules to identify taxpayers with assets outside their home countries.
The UK was an early adopter of the Common Reporting Standard but now more than 100 jurisdictions exchange information like this with the aim of tackling cross-border tax evasion.
The latest figures show that tax authorities are increasingly requesting more detailed records from HMRC so they can confirm taxpayers have paid the correct amount of tax.
John Hood, of accountancy firm Moore Kingston Smith, said HMRC’s own data-gathering powers had fuelled the rise in targeted international requests. “HMRC has enhanced its powers to access information in the UK to assist foreign tax authorities,” he said.
For example, the introduction of the Financial Institution Notice (FINs) in 2021 gave HMRC the authority to obtain data from banks and other financial institutions as part of tax investigations. Unlike standard notices to banks, a FIN can be sent without approval from a First-Tier Tribunal or consent from the taxpayer. In 2024-25, HMRC issued 173 FINs to help with international requests, according to the latest data.
An HMRC spokesman said: “We’ve led the way in increasing global tax transparency, enabling us to effectively tackle offshore tax evasion and avoidance, and ensure everyone pays the right tax under UK law.
“Information sharing with our international partners also helps us to better target our compliance activity on the small minority who seek to break the rules.”
Separately, HMRC has sent thousands of so-called “nudge letters” to taxpayers to clamp down on offshore tax evasion.
HMRC has a time limit of six years to investigate tax lost through careless behaviour, but this extends to 12 years for offshore tax matters.
