David Cameron, the British prime minister, has announced that the forthcoming register of beneficial owners of corporations - but not of all types of trust - will be open to the public.

David Cameron, the British prime minister, has announced that the forthcoming register of beneficial owners of corporations - but not of all types of trust - will be open to the public.

This is thought to be a positive move for compliance officers and especially money-laundering reporting officers with the job of conducting 'know your customer' checks on customers to see if they own more than 25% of an entity. Without automatic public access, many argued, it would be difficult for such people to check data at the frequency needed for today's pace of business.

The figure of 25% is an old one, dating from 2005 when the European Union was debating how much of a company a shareholder might need to pervert its use for money-laundering purposes. The implacable opposition of Silvio Berlusconi, the Italian prime minister of the day, kept the figure high. At that time the banks of the UK were observing an informal figure of 10%.

The proposal for a register to be kept at Companies House, the UK's repository for all publicly-held information on corporations, came from a 'Group of 8' meeting in mid-June at Lough Erne in Northern Ireland. Many wealth managers at many conferences since then have warned that the exposure of ownership of funds and corporations could threaten the security of vulnerable, mentally ill or otherwise incapable high-net-worth individuals. The original policy document, issued by Vince Cable's Department for Business, Innovation and Skills, left the question of access to the records open for further discussion. The prime minister seems to have settled the matter unilaterally.