The UK's head of tax, Lin Homer, has admitted to MPs that typical telephone waiting times of over 4 minutes do not include the time spent listening to recorded messages, which can be more than 2 minutes.
HM Revenue & Customs is setting itself a new target, from April, of making 80% of people wait no longer than 5 minutes to speak to a real person, including recorded messages.
Lin Homer, chief executive and permanent secretary at HMRC, was answering questions from the Commons Public Accounts Committee, in the wake of a National Audit Office report which calculated that taxpayers were losing £136m a year in call charges and wasted time.
Last year, HMRC failed to answer 26% of calls - or 20 million calls in total. Of the callers who did get through, millions had to wait more than 10 minutes.
Over the winter the proportion of calls not picked up has fallen to around 10%.