"Prudential Financial's fax number is accurately listed on all of our forms and communications," the company said in an e-mailed statement. "Effective immediately, North Regent RX will forward to Prudential Financial all faxes it has received, as well as any it may receive in the future."

Initially, North Regent contacted the doctors' offices, clinics and even patients directly when it received a fax meant for Prudential. But the company doesn't have the resources to continue doing that, Baxmeyer said. "What happened was it became a point of distraction for us. It would have taken an effort that we were not capable of."

According to Baxmeyer, North Regent in April offered to sell its toll-free number to Prudential for a fee that included the costs of acquiring and publicizing a new toll-free fax number for North Regent. Another option it suggested was for Prudential to give North Regent some sort of legal protection for receiving the unsolicited confidential information, he said.

Both requests were turned down by Prudential, which instead asked North Regent to simply forward all of the faxes it received back to Prudential via prepaid mail, Baxmeyer said. Prudential also informed North Regent that it had sent out a memo urging doctors offices and clinics to use extra caution when sending claims via fax.

John Pescatore, an analyst at Gartner Inc., said that Prudential cannot be held responsible for mistakes made by others. "In this case, the person who is sending out the information is the one that's responsible. Prudential did not give them the wrong number."