HMRC have issued a note concerning problems with their online self assessment service, following complaints from tax advisers.
General account details, tax return statuses and payment details are currently not being updated - and, according to anecdotal evidence, they haven't been refreshed for several days.
It is expected by users that amendments appear on the system in real time.
'This is under investigation and should be resolved shortly,' according to the notice on the Revenue's website.
One Taxation reader said that some of his clients' information had not updated for at least 11 days, and on at least one occasion a tax return was submitted online only for HMRC to later deny any knowledge of the document. (Although they later admitted to having received the return.)
Another reader told us that he registered as an agent in March and received a user ID, an agent ID, and a list of UTR numbers, some of which did not belong to any of his clients.
He contacted HMRC about this error but 'was unable to proceed any further. Calls to the helpline were less than helpful'.
Our reader tried to re-register last month with a new user ID, and is now told by the online system, whenever he tries to log on, that there is no record of his existence.
He has written to the taxman's customer care section - 'out of desperation' - but has so far received no response.