Sure has been fined £80,000 by the Data Protection Authority over breaches arising from last year's phone book.
The Authority says the phone company published personal data that was inaccurate and against the wishes of subscribers.
It says there was also a lack of transparency in how the firm processed customers' personal information in the 2019/2020 telephone directory.
This is the first fine that has been imposed under the new law.
Although the penalty is substantially lower than the maximum permitted, Data Protection Authority Chairman Richard Thomas says he hopes it will bring home the importance of taking great care with people's personal information.
"The data protection law provides organisations with a range of accountability tools to ensure appropriate technical and organisational measures are in place including being prepared to deal swiftly and effectively with any breach. In taking this action, the Authority has responded appropriately and proportionately to the evidenced compliance failures. We welcome the positive steps Sure have taken since this incident to ensure better data governance of the personal data in their care.” Data Protection Commissioner, Emma Martins,
Sure 'disagrees profoundly' with the findings of the investigation.
The company has apologised to customers affected by the errors and says it is now taking time to consider the ruling in detail before responding formally.
"However, we are disappointed and surprised by the ODPA's ruling which follows on from what, in our view, was a flawed and unfair investigation process. This included a lack of full disclosure about the specific matters of concern to the ODPA, which in turn made it difficult for us to participate meaningfully with the process.
From our initial review of the ruling we disagree profoundly with the findings of the ODPA's investigation, some of which were not put to us during the investigation and some of which are in our opinion factually incorrect. As such, we are now considering the ruling in detail before we formally respond.
As part of our programme of continuous improvements we have made changes to how we compile and produce the directory going forward, based on feedback we received last year, to prioritise the accuracy of customer data and customer satisfaction. We note that these positive steps are recognised and welcomed by the ODPA in their media statement."
The changes have included allowing all customers to check their directory entries before it is printed. Production of the 2020/21 phone book has been delayed because of the coronavirus pandemic. It is due to be available in November.
Neither the ODPA or Sure would comment further.