The Chicago Tribune reports: In late January, Citibank mailed year-end tax statements to 600,000 Citi customers via the U.S. Postal Service that included the customers’ Social Security numbers … on the outside of the envelope.

Citi called the mistake a “processing error.”

Although the nine-digit numbers were not identified as Social Security numbers (they were printed at the lower edge of the envelope with other numbers and letters and resembled a mail routing number), Citi still reacted to the mistake. EVP and Director of Citibank Client Services Norman White sent customer notification letters to every affected Citi customer during the week of Feb. 15, apologizing for the error.

The letter offered Citi customers the option to enroll in a free, 180-day credit monitoring service arranged by Citibank, but White also encouraged customers to regularly review activity on their accounts.

Citibank said in a statement that the company believes the error produced little to no risk to its customers and that it has been corrected for all Citibank’s future mailings.

“Although there is little or no risk to our customers, we decided to be completely transparent to our customers by notifying them of the error,” the statement said. “It is an important part of our commitment to our customers to be fully transparent and to give them the peace of mind that comes from banking with people they trust.”

Full text of Citibank’s notification letter:
We are writing to inform you that due to a processing error the nine digits in your Social Security number, along with a string of other numbers and letters all resembling a mail routing number, were printed on the lower edge of an envelope containing a year-end tax statement that we mailed to you recently.

We believe there is little or no risk to you. However we wanted to bring this to your attention, apologize and confirm that changes have been made for all future mailings.
 
Should you nonetheless remain concerned, we have arranged for you at your option to enroll in a credit monitoring service at no cost to you for the next 180 days. To activate this coverage, please call the toll-free number or visit the website listed below and enter the redemption code. The redemption code is required for enrollment. As always, we encourage you to regularly review activity on your accounts.
 
For credit monitoring service coverage:
Toll-Free Number: 1-866-212-9114       
Website: www.identityguard.com/alert   
Redemption Code: _______________       
 
We are sorry for any inconvenience this may have caused you. Do not hesitate to contact us at 877-478-6597 if you have any questions.
 
Sincerely,

Norman Wright
EVP & Director, Citibank Client Services

(Source: http://newsblogs.chicagotribune.com/)