Pensioners’ private and confidential information has been unwittingly handed out to the public by the council.

A “printing error” lead to pensioners receiving their P60 forms, which on one side featured their own, correct form and on the reverse a stranger’s P60 form, complete with their national insurance details, addresses and other private information.

The mistake was spotted by one Walthamstow resident, James O’Rourke, whose mother-in-law received a double-sided P60 with someone else’s details on the reverse.

He flagged it with the Waltham Forest Council on Facebook and said: “It appears Waltham Forest Council has yet again been frivolous with its residents’ data.

“My mother-in-law, a former council employee, received her pension P60 this week. To her horror it had been printed upon on both sides, the reverse side being another person’s P60.

“A few days later she received another P60 with an attached letter. No reassurance as to whether her data has not been so sloppily dealt with.

“This is not the first time the council has breached the Data Protection Act this year, so the Information Commissioner’s Office must take immediate action and the ultimate person responsible taken to task.”

The attached letter from the council said: “As you are aware, every year you receive your Pension P60 detailing your annual pension earnings.

“Due to an error with our printing partners a small number of these were printed with information on the reverse relating to another customer. We sincerely apologise for this error.

“Please destroy the P60 you were sent originally immediately and securely, using a home shredder if possible.

“You can also send this to the council if you would like us to destroy this for you.

“I can assure you we are taking steps to prevent any future occurrences of this type of error in the future.”

A council spokesperson said: “We take protecting people’s data very seriously and are very sorry for any concern caused.

“We were made aware on Thursday May 23 of an error by our printing partners affecting one batch of our pensioners’ statements. We immediately investigated and isolated the issue, and have implemented additional sign off procedures to prevent this happening again.

“An immediate apology letter was sent to everyone affected alongside new P60 pension statements. We would like to reassure anyone who received such a letter, or is concerned that their information may have been received by someone else, that there is no risk of fraud because of it. The batch contained over 3,000 incorrect statements.”