An accidentally mistake puts Verizon customers in jeopardy of identity theft.

Verizon Wireless distributed a file with limited details on more than 5,000 customers outside the company, potentially giving identity thieves a startup. The file was distributed by mistake says Verizon.

The Microsoft Excel spreadsheet file was e-mailed on Monday and includes names, e-mail addresses, cell phone numbers and cell phone models of 5,210 Verizon Wireless customers. According to the spreadsheet, all the customers have Motorola Razr mobile phones.

The spreadsheet was inadvertently sent on Thursday to about 1,800 people, all Verizon Wireless subscribers and the Excel file was attached to an ad for a Bluetooth wireless headset, instead of the electronic order form that was supposed to be sent.

“Verizon Wireless takes the security, confidentiality and integrity of your personal information very seriously, and we deeply regret this error,” the company said in the Thursday e-mail. It said that it has already implemented additional quality control procedures and process improvements to prevent a re-occurrence.

While the privacy breach in no way makes identity theft automatic, it helps put a clever fraudster in the starting blocks, said James Van Dyke, the principal analyst at Javelin Strategy & Research in Pleasanton, Calif., which tracks identity fraud.

“To commit ID fraud, you must do several things well. This just makes the job slightly easier,” he said. “For example, with this list in hand, a fraudster could call the listed numbers, pretend to be a Verizon Wireless representative and ask the subscriber for information to update the account.”

Of course that the reactions appeared shortly after the announcement.

One Verizon Wireless customer whose details were included in the file said he was upset about the incident. “Someone just got incredibly careless sending out a sales e-mail,” said Frank Donley. “With all the privacy incidents you read about recently, I should feel relieved that my credit card number, Social Security number or some other secure info wasn’t released.”