ID theft cost British businesses £50m in 2005, and this is set to increase by 1,300% by 2020 to £700m.

According to British businesses, corporate ID theft is one of the fastest growing risks they face - and it is large businesses that are most likely to be affected. These were findings from research commissioned by Royal & SunAlliance (R&SA) and carried out by the Centre for Economics and Business Research.

Corporate identity theft happens when fraudsters trade under a legitimate company's credit and name. Assets can be stolen and bank accounts emptied.

According to the R&SA research, businesses with over 250 employees will pick up the biggest share of the cost of corporate identity theft, while London firms are forecast to suffer the greatest increase in costs. The sectors most likely to be affected are communications, banking, finance and insurance.

Simon Wallace, Centre for Economic and Business Research, commented: "We are on the edge of a potential boom in corporate identity theft. With almost universal computer usage and internet coverage in the business environment, the potential for corporate identity theft is more significant than ever. Those willing to hack, scam and defraud will find new, technically advanced methods to open loop holes and steal a firm's identity. Business will need to adapt to this risk and must be willing to increase its spending on improved IT security systems in order to stay one step ahead."

R&SA issued the following guidelines for companies to help combat identity theft:

- Check your company details are correct at Companies House.

- Sign up to Companies House Monitor system - an email alert warning the password holder when any changes to company details are lodged.

- Sign up to the Companies House PROtected Online Filing, or PROOF. which enables companies to file specific forms in a secure environment.

- Check prospective employees' CVs and use recruitment security checks. Many scams still require an insider.

- Own all the permutations of your company name so that fraudsters cannot set up a rogue website or contact your customers from an e-mail address that looks legitimate, for example royalsun.com, royal-sunalliance.com, royalandsunalliance.com Remember to register both.com and.co.uk variations.

- Make sure all employees have secure passwords that are not written down.

- Dispose of company stationery, including letterheads and bank details, in a secure way.

For further information you can download the R&SA Guide to Corporate ID Theft at a www.royalsun.com