If you receive a check of self assessment tax return, we suggest you begin by reading our article – Why have I been selected for tax investigation? It provides some useful background information on case selection, prior to beginning an HMRC check of self assessment tax return.


You need to consider the language used by HMRC in any check of self assessment tax return very carefully. Do not be fooled by what can appear, at first glance, to be a very friendly customer service enquiry.

HMRC begin by saying – “Every year we check a number of returns to make sure they are correct and that our customers are paying the right amount of tax.” You almost feel that you have been randomly selected?

These checks are rarely a random affair. Random checks account for a tiny percentage of the overall number of compliance checks started by HMRC each year. The reality is that over 90% of HMRC checks are launched following a thorough risk assessment.


Section 9A TMA 1970 is precisely the same tax investigation legislation applied by HMRC prior to launching this latest compliance check initiative. However friendly the language may appear to be in a check of self assessment return, you should, without question, consider yourself under tax investigation with all of the associated implications. If you have received a letter from HMRC informing you that a check of self assessment tax return has commenced, the Inspector clearly feels that tax is at risk. In short, HMRC feels that tax has been underpaid. They are looking to recover it for the year of investigation and if applicable for earlier years too.

HMRC’s action will be determined by the nature and scale of the tax underpaid. If HMRC decides that your conduct during the year of investigation applies to earlier years – and the tax loss is significant, they will look to scale the irregularities back. You can be sure that HMRC will not write to you and commence this process without first doing their research. They will have compiled a comprehensive intelligence file, including information from third parties.

Visit our page outlining HMRC case selection prior to a check of self assessment tax return for more information. Clearly, HMRC makes mistakes in just the same way that we all do. They could be wrong!! That does not mean that you are not compelled to provide them with all relevant information and documents as required by them.

We have written an article covering requests for information and documents during an HMRC compliance check.

Get in touch

No need to panic. Do not panic! Specialist help is out there. If you are worried, following receipt of a letter notifying you that HMRC has commenced a check self assessment tax return, then please call our friendly team for specialist tax investigation advice. You can reach us day and night by calling 0330 999 5000.