Many businesses must register with the ICO under the Data Protection Act (DPA). Registration costs £35 a year. Any company which is a data controller as defined in the DPA must pay the fee to the ICO.
Several people have been jailed in the past for charging significantly more than this to firms by posing as agents of the ICO.
Williams obtained over £400,000 by his fraud over a period of 15 months between December 2002 and April 2004.
Williams posed as an agent of the ICO, demanding between £95 and £125 for registration. He and an accomplice ran a number of agencies perpetrating the scam.
The judge in the case said that the ruse was "a well planned and sophisticated offence led by greed and cloaked in officialdom".
The ICO worked with Merseyside Police and Trading Standards officers to investigate the activity.
"We are very pleased with the outcome of this investigation," said Simon Entwisle, chief operating officer of the ICO. "The ICO will continue to work with other authorities to bring people to justice who try to extort money from businesses in this way.”
Four men were jailed by Liverpool Crown Court earlier this year after running similar schemes. Francis Boyd obtained £400,000 over a 15 month period and was jailed for two and a half years in January. Three other men working with Boyd obtained a further £200,000 in the schemes.
