Bill Ford had never dealt with Great Western Financial and had no reason to believe the company had collected detailed records of his financial affairs.

That impression was shattered, however, when Great Western sent Diane Lowe, his landlord, a letter suggesting Lowe and Ford apply for a Great Western consolidation loan and listed his creditors, how much he owed and his monthly payments.

Lowe was equally surprised, for she had never dealt with Great Western either, and the letter provided similar detailed information about her credit card balances. (Both Ford and Lowe are pseudonyms.)

Great Western, one of California's largest savings and loans, said it hasn't done anything wrong, except for making a second round of credit checks last month.

''What our consumer finance department did is not unusual in the industry,'' said Lynn Taylor, director of public relations. ''It's nothing that many financial groups do not do.''

If that's true -- and it appears to be -- much more needs to be done to protect individuals from having details of their finances given to others without their permission.

Federal privacy laws limit the collection and dissemination of credit information, but the laws are imprecise and are interpreted differently by creditors and consumer advocates.

Ford's relationship with Great Western started, unknown to him, last November when he was out of the country.

Lowe, who rents a room in her Mountain View, Calif., home to Ford, went to Carpet Town to buy carpeting and applied for credit. She listed Ford on the credit application. She doesn't remember why he was included; Great Western says he was listed as a co-applicant.

Lowe decided not to buy the carpet and thought no more about her trip to the store. However, it had ramifications that eventually made the trip unforgettable.

That's because Carpet Town doesn't do its own financing. The store uses Great Western and sent to it information Lowe had provided.

Lowe's credit status was easy to obtain from credit bureaus because she had listed her name, address and Social Security number.

Lowe doesn't believe she wrote down Ford's Social Security number. But Great Western had his name and address, which is usually enough information to obtain a Social Security number from a credit-reporting service.

Great Western did a credit check on Ford in November and again last month before it sent out its loan consolidation offer. Why did it do so without his authorization? ''We have to rely on our agents'' -- in this case Carpet Town -- to send Great Western only authorized credit applications, Taylor said.

Since Ford ''never made any overtures to the carpet store or to Great Western, there was no permissible purpose in obtaining a report on him, period,'' said David G. Grimes Jr., an attorney with the division of credit practices for the Federal Trade Commission.

Once Great Western had the information, it had no right to provide it to Lowe without Ford's permission. Financial institutions are prohibited from disclosing one person's information to another, without authorization, even if they're husband and wife.

Why was the information given to Lowe? ''They live at the same address,'' Taylor said. ''We don't look into relationships. We can only assume that the sales representative who sent the letter to Diane didn't realize it would be offensive to anyone.''

Great Western had every right to do a credit check on Lowe last November, when she applied for credit.

But Great Western conceded it shouldn't have done another. ''It is not our normal procedure to pull a second one like that, and it shouldn't have been done,'' Taylor said.

While it may have been legal for Great Western to use data obtained in November for its July marketing campaign, some consumer advocates believe it shouldn't have been. That problem would be taken care of by legislation being considered by the consumer affairs subcommittee of the House Banking Committee.

The legislation would require that the information a credit applicant supplies be used only for the purpose for which it was submitted. A financial institution wouldn't be able to use the data in its files for anything it wants.