Restaurant and cafe owners should be storing contact details of customers securely, out of sight of other clients.
That is the view of the Data Protection Commission after some concerns were expressed over the current practice.
The details have to be kept for contact tracing purposes.
Deputy Commissioner at the DPC, Graham Doyle, said business owners need to make sure personal details are stored away from other customers.
Mr Doyle said: "The storing is important, whether it's manual or digital, it must be kept secure and confidential.
"So in circumstances where somebody is using a sheet of paper to record the information, they should record the information when somebody walks into the premises but then store the information away so that a member of the public cannot see it and the only people who are actually accessing it are the staff members themselves."