HMRC customer service levels have plummeted to such lows that the majority of entrepreneurs say it is now affecting their business.

A survey by the Association of Chartered Certified Accountants (ACCA) shared exclusively with This is Money found 89 per cent of business owners said poor levels of service at the tax office is having a negative impact.

Just one per cent said HMRC service had a positive impact on the running of their business.

Despite accountants and business owners raising concerns with HMRC, standards have only deteriorated.

The same survey taken in March found that 66 per cent of business owners said HMRC was affecting their business negatively, with just 52 per cent saying the same in October 2023.

In a letter to the Chancellor ahead of the the Budget, ACCA said: 'It is difficult to overstate levels of concern and frustration being experienced by a substantial proportion of our members in their contact with HMRC and the impact this has on their clients' businesses.

'This includes significant delays by HMRC which cost taxpayers, agents and HMRC time, as well as failures from HMRC in dealing with basic processing requests, like VAT registration, through to more complex areas like dealing with R&D tax credit enquiries.'

We first highlighted issues with HMRC services last year, ahead of the permanent closure of HMRC's VAT registration helpline.

Readers spoke of their frustration that they were unable to get through to an HMRC agent, with some saying the delays had made them consider moving their business abroad.

An HMRC insider told us that a 'culture of fear' and too much micro management had been behind the delays.

ACCA members highlighted communication as the priority, with 91 per cent calling for a reduction in call waiting times.

Data from accountancy firm UHY Hacker Young found that taxpayers spent 719 years on hold to HMRC in the past year.

The average call length has increased 19 per cent, from 22 minutes and 41 seconds to 71 minutes and two seconds.

ACCA has highlighted that the government and HMRC need to do more to 'recognise the value of timesaving and trust' offered by HMRC's trained agents.

It also said that the making tax digital initiative is 'overly complex' which has knock-on effects for small businesses and the self-employed, as well as HMRC itself.

It is calling on the government to invest more in HMRC to improve customer service and deliver the 'modern, efficient tax system we need'.

A  Government spokesperson said: 'We are committed to improving customer service performance at HMRC, and the Chancellor will set out more details at the Budget.'