The pioneering site, besieged by teething problems since its launch two years ago, has been suspended after users reported seeing information from other taxpayers.
However, the agency has moved quickly in an attempt to reassure customers.
An official Revenue statement, read: ‘The security of our customers’ data is of paramount importance to us.
‘A very small number of people told us that they had seen data relating to other people. When we learnt that we decided to temporarily withdraw the SA On-line service and we are now working around the clock to get to the bottom of the problem.
‘It is still possible to send in returns on line using an alternative product.’
Crowe Clark Whitehill , the top 20 accountancy firm, has announced the promotion of Chris Mould to partner
The latest opinions from Accountancy Age on Making Tax Digital, and outline plans to evolve the UK's corporate governance regime
Five million taxpayers are ow using digital personal tax accounts (PTA) as part of the making tax digital strategy, HMRC said
UK-based non-doms have paid ten times more tax than the average taxpayer, raising concerns over the Brexit impact on non-dom contributions and therefore, the economy