Members of the European Union have agreed to draw up a blacklist of tax havens in the wake of the Panama Papers leaks.
Finance ministers have endorsed the move, which is to be completed by the end of the summer.
The European Commission says countries on the tax blacklist should be sanctioned if appeals for change go unheeded.
Ministers have also agreed to exchange information on the beneficial owners of companies and the EU is planning a crackdown on banks and tax advisers who help clients hide money offshore.
Currently the 28 EU states have different national lists of tax havens and can decide individually whether to impose restrictive measures.