Nearly half of Canadians say they have refused to give personal information to a retailer, according to a survey commissioned by the federal privacy commissioner.

The survey also found that one in two Canadians said they have questioned a retailer why they need a name, postal code or address.

Consumers said they were reluctant to provide names, addresses and postal codes to retailers, citing fears of fraud and identity theft. About a quarter of the respondents also said they could see no reason for the retailer to collect the data.

The results indicate consumers are showing a considerable amount of savvy, Privacy Commissioner Jennifer Stoddart said Thursday.

"Our personal information is increasingly invaluable in the marketplace, and I am very pleased to hear that consumers are taking charge and questioning requests for their information," Stoddart said in a release.

"I recognize that businesses have a need to better know and understand their customers, but if they can't give you a good reason for why they need your personal information, simply don't give it out."

The survey also found 13 per cent of respondents have provided false information.

The telephone survey, conducted by Ipsos-Reid, was conducted Dec. 11-16, 2007 and involved approximately 1,000 adults. The margin of error is 3.1 percentage points, 19 times out of 20.