The tax office helpline has been branded a 'lottery' with almost a third of callers cut off before they even get to speak to an adviser, according to new research, the DailyMail wrote.
The average waiting time to speak to a real person was 18 minutes - with one person left hanging on the line for 41 minutes.
Consumer champions Which? tested Her Majesty's Revenue and Customs (HMRC) helplines ahead of the self-assessment tax return deadline on January 31st.
Which? researchers made 100 calls to HMRC's self-assessment and general enquiries helplines to see how easy it is to get through to an adviser.
Nearly a third of the calls (29 per cent) were cut off by the automated system before the caller could speak to anyone, with callers being told it was because the helpline was 'very busy'. In the 71 calls where researchers did manage to get past the automated system, they were then put on hold. On average it took 18 minutes to speak to a real person, but one caller was left waiting for 41 minutes.
The Which? researchers found the later in the day they called, the longer the wait and the more likely they were to be cut off.
The automated system also struggled with certain words and phrases. A query about 'my tax code' was fine but when asked 'Do I need to pay tax on premium bond winnings?' it asked if the caller was changing a name, or asking about a VAT surcharge notice.
In a separate survey of more than 1,000 Which? members, one in five (20 per cent) who had contacted HMRC in the last year said they found contacting them difficult, compared with 15 per cent of those who contacted the Department of Work and Pensions, 12 per cent who contacted their local authority and eight per cent who contacted the DVLA.
Richard Lloyd, Which? executive director, said: 'We've found people could face lengthy waits or even be cut off when trying to get assistance from HMRC's helplines. 'With large numbers of people soon to be seeking help with their self-assessment tax return, we want to see HMRC doing more to monitor and improve their call-waiting times.'
Which? said it had shared its findings with the Treasury and HMRC and have also briefed the Public Accounts Committee.
Hopefully this might help them to improve their automated and phone systems in time for the Tax Deadline on the 31st of January.