A Aug. 11 Business article describing how Verizon Communications Inc. mistakenly published thousands of unlisted phone numbers misstated Harry J. Mitchell's job title. He is director of media relations for Verizon's mid-Atlantic bureau. (Published 8/12/04)

As many as 12,000 telephone numbers that Washington area customers had paid to keep out of the phone book may have inadvertently found their way into directories as a result of a computer foul-up, Verizon Communications Inc. acknowledged this week.

Verizon said it offered to refund affected customers any fees they paid to omit their numbers from the directories. The company also offered to change their phone numbers at no charge.

The phone giant said it first caught the mistake in late April in response to a customer complaint but did not begin notifying other affected consumers until June, when it became clear that thousands of unlisted numbers had mistakenly been made public.

At least 9,000 of the names were published in Verizon's SuperPages covering Virginia, Maryland and West Virginia. But the nation's largest telephone company provided even more unlisted numbers, as many as 12,000, to rivals that publish their own directories, according to Harry J. Mitchell, director of marketing for Verizon. (Verizon is required by law to make its telephone listings available to others.)

Rival directory publishers were not notified of the problem until July, and it is unclear how many unlisted numbers were published in non-Verizon telephone books. "We were basically getting a feel for how many listings there were. It took a while to make that happen," Mitchell said.

Although Verizon caught the problem in time to avoid publishing unlisted numbers of any D.C. residents in its SuperPages, their names and numbers may still show up in rival directories, Mitchell said.

Unlisted numbers differ from what are known as unpublished numbers. Unlisted numbers are not published in phone books, but they are available through the 411 directory assistance. In contrast, unpublished numbers are not listed in telephone books and are unavailable through directory assistance.

Only three unpublished numbers were released along with the thousands of unlisted numbers, according to Mitchell. An internal review found that Verizon began publishing unlisted numbers as early as mid-2003. Verizon blamed the problem on an effort to convert to a new computer system.

Consumers pay a fee to have their telephone numbers omitted from local phone books. The fee varies from region to region. In the District, the fee is $5.16 a year. In Virginia it costs $12.72, and in Maryland the charge is $13.20. West Virginia residents pay $16.68 to keep their numbers out of telephone directories.

There are a variety of reasons for having an unlisted number, according to Mitchell. In some cases, people want to avoid telemarketers who assemble their call lists from the names in phone books. In other cases, people may want to avoid listing a specific line, such as one dedicated to a fax machine.

According to a copy of a letter Verizon sent to one D.C. customer, who forwarded it to The Washington Post, the phone company promised to refund the fee for having an unlisted number and offered to change the telephone number at no charge.

"We were able to correct the error before our directory was published so your listing still does not appear in the Verizon directory. It may appear, however, in the directories issued by other publishers who received your listing from Verizon before the error was corrected," the letter stated.