How far back can HMRC investigate?

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If you are subject to a tax investigation, you may be wondering how far back HMRC can go as part of their enquiry. Your tax affairs can be investigated for a number of different reasons. The period of time that HMRC considers will depend on the circumstances of your case.

How far back can HMRC go in a tax investigation?

The HMRC investigation time limit is 4 years if an innocent error is suspected; where mistakes in tax returns are deemed careless or negligent, the window extends to 6 years. Suspicion of deliberate tax evasion warrants an investigation period of 20 years.

HMRC will therefore investigate further back the more serious they think a case could be. The investigation will often start with an enquiry into the last year’s tax return, and must be commenced within 12 months from when this was filed.

During their investigation into your most recent documents, HMRC will attempt to determine if:

  • There have been no mistakes, in which case they can close the investigation;
  • The mistake was due to an innocent error, in which case they may go back 4 years;
  • The mistake was due to your negligence, in which case they may go back 6 years;
  • The mistake was a deliberate attempt to avoid paying tax, in which case they may go back 20 years.

At any stage in the investigation, HMRC may change its stance on the reason for any mistakes or omissions. For example, if it initially believes that a mistake was a one-off, innocent error but then finds grounds to suspect ongoing negligence, the investigation will be extended to look further back resulting in HMRC requesting more information.

HMRC can also start investigations into an individual’s finances upon information it receives from sources other than the tax return, such as Land Registry information or overseas banking details which can trigger an enquiry. These investigations can go back a similar length of time. Read more on how you can find out if HMRC is investigating you.

Seeking specialist advice

Of course, the further back the HMRC wishes to look, the more stressful and difficult a tax investigation can be for many people. The amount of information and detail requested by HMRC can be overwhelming so it is important to obtain specialist advice at an early stage to ensure you make the right decisions, including challenging HMRC if it is appropriate to do so.

Regardless of what stage of a tax investigation you are at, if you haven’t spoken to a lawyer yet we recommend you doing so. If you would like to find out how we can assist to answer your concerns and resolve your problems, we are very keen to provide an initial, no-obligation consultation by telephone or email (whichever we think will be the quickest and clearest for you) to confirm – if we can help you (we usually can), how we can do this, and to give you a costs estimate so that you can decide if you wish to proceed. Get in touch with us today.

We confirm that we will treat any information you give us as strictly confidential and purely for the purposes of responding to you. When you formally become a client, in addition to solicitors confidentiality, you will also be covered by Legal Professional Privilege (which only applies to solicitors and not accountants or tax advisers) shielding disclosure to third parties seeking information.

Visit our tax investigation advice page or speak to our solicitors for more information.


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