Proposed regulations in the US could force UK charities that raise funds there to carry out more reporting and due diligence, according to the Charities Aid Foundation's sister organisation.
Susan Saxon-Harrold, chief executive of CAFAmerica, which distributed almost $10m worth of grants from American donors to non-US charities last year, said regulations being examined by the Senate were likely to be introduced before March.
They would affect charities receiving grants from the US and 'friends of' organisations - those registered as charities in the US to fundraise for British groups.
The changes have been prompted by increased security concerns over fundraising for foreign organisations following the 11 September attacks.
"It is being proposed that charities should be audited every five years to determine whether they deserve tax-exempt status," Saxon-Harrold explained.