The laptop was mislaid in transit
A laptop computer from the Citizens Advice Bureau in Coleraine has gone missing.
The details of about 7,000 people were on the computer of an outreach worker from the voluntary group which was mislaid in transit.
Office manager Angela Walsh said people should be reassured that no financial information is at risk.
"There's no danger to the information, the laptop, is triple protected and heavily encrypted," she said.
"We took advice from the Information Commissioner immediately and followed his advice to the letter.
"A mistake has happened and we are notifying everyone involved to reassure them."