Switzerland and the UK have signed an agreement to begin taxing funds held by wealthy British clients of Swiss banks from January, after altering the terms of a deal to appease the European Commission.
The Swiss are racing to finalise arrangements with Britain and Germany to give its banks enough time to plan to levy the tax before it goes into effect in 2013.
The British accord is significant because it contrasts with opposition in Germany to a similar deal.
The EU dropped its opposition to the British deal two weeks ago after Switzerland agreed to bring the pact into line with EU rules.
Specifically, interest income will now be subject to an existing EU-Swiss agreement of 35 per cent, plus an additional 13 per cent to ensure tax compliance, adding up to an unchanged rate of 48 per cent tax.