Members of Congress said

As many as four million calls to HMRC each year, taxpayers and businesses “in the dark” put taxpayers and businesses “in the dark” as they try to drive the UK’s increasingly complex tax system.
The figure emerged at a hearing on the House of Commons Business Committee last week, with MPs asking officials about the ability of the tax authorities to collect £46.8 billion in taxes owed but not yet recovered.
Labor MP Liam Byrne imposed a level of customer service to HMRC executives, asking how many calls the public had not been answered. In response, HMRC Director-General for Client Strategy and Tax Design, Jonathan Athow, acknowledged that since the department responded only 85% of calls, unresolved phone numbers could reach “there could be 30 million, maybe three to four million calls.”
The revelation has sparked sharp criticism from the tax community, with the industry warning that support risks are insufficient and undermining compliance and the government’s own revenue targets.
Seb Maley, CEO of tax insurance provider QDOS, said the situation is causing millions to work hard to get their obligations.
“The HMRC leaves millions of taxpayers and businesses in the dark, and the HMRC misses three to four million calls a year, which is shooting under his feet,” Maley said.
“Behind every missed call is someone trying to do the right thing – whether it’s paying taxes or seeking guidance to ensure compliance.
Although the HMRC has promised to improve services after growing criticism, industry insiders stressed that if the government has the opportunity to close the tax gap, it must make rapid progress.
“Every unresolved call is a missed opportunity that can help people meet their tax obligations fairly and effectively,” Maley added.
The warning is a tough time for HMRC, which faces increasing pressure in the long delays, declining staffing levels and attempts to push taxpayers toward digital services only. Members of Congress and professional bodies have repeatedly called for urgent action to restore confidence in their frontline support.
Experts believe that there is a billion dollar danger, and improving taxpayer participation is no longer just a matter of customer service, but a matter of financial necessity.