The NAO audits HM Revenue & Customs' (HMRC) £4 billion-plus
annual expenditure, and through the Trust Statement the
approximately £450 billion of revenues and £30 billion expenditure
on the taxes and duties it manages. HMRC administers the majority
of UK taxes, as well as national insurance contributions, EU
customs requirements, and tax credits.
'Section 2' audits determine whether HMRC’s regulations and
procedures are able to check effectively on the assessment,
collection and allocation of revenue.