The purpose of an HMRC tax investigation may seem like a very straight forward issue, after all we should all have an understanding of the basic phrase. But when spoken together the words tax and investigation are rarely good news. Actually, many do not realise that there is no standard definition. Investigative contact made by HMRC can come in many forms, some are wholly more serious than others. Here we will attempt to cut through the technical jargon and give you the no nonsense, practical advice that you need.


A tax investigation is an enquiry launched by HMRC into the tax affairs of a UK individual, business or other entity. It can cover the range of taxes which come under HMRC jurisdiction – for example income tax, corporation tax, capital gains tax, tax credits and VAT. An HMRCinvestigation generally commences when HMRC have concerns regarding information that has been supplied to them via a self assessment tax return. A tax investigation can also begin if HMRC identify a UK resident who is operating in the hidden economy. In other words, an individual or business who is not in the tax system. A very small percentage of tax investigations begin randomly. So if you receive a tax investigation letter from HMRC you can be reasonably sure that they feel you have underpaid tax.


HMRC tax investigations come in many guises.

We have individual guides dedicated to each, so you can save time by reading the page that is most relevant to you:

  • COP 9
  • HMRC Special Investigations
  • Civil Investigation of Fraud
  • Check of self assessment tax return
  • HMRC compliance checks
  • Contractual disclosure facility
  • VAT investigations
  • Tax credit investigations

Even if HMRC have not been in contact. If you are concerned that you may have underpaid tax for any reason then you should consider making a voluntary disclosure now, before it is too late. An umprompted voluntary disclosure with the right tax investigation advice will see you benefit from generous settlement terms.

Get in touch

If you wish to discuss any aspect of this article, then please contact Admiral Tax Investigations today on 0330 999 5000. We will respond to tax investigation enquiries submitted via email within the hour.