HMRC conducts a wide range of enquiries into taxpayers’ affairs, from simple checks to full-scale fraud investigations. The HMRC Fraud Investigation Service (FIS) normally carries out the most serious enquiries, which can take considerable time and cause you significant stress.

Going through an HMRC investigation can be a difficult and costly process. Getting the right help not only makes this process a lot smoother, it can also significantly reduce the overall financial costs.

We support many taxpayers, including individuals, companies and partnerships, through a broad range of HMRC investigations. Using our extensive experience and knowledge of the process, we provide bespoke tax investigation advice to help you achieve the best possible outcome.

If you are subject to an HMRC investigation, please do not hesitate to get in touch with us directly on +44 (0)800 032 8374 or

Code of Practice 9

If HMRC suspects that a taxpayer has committed tax evasion, it may undertake a tax fraud investigation. As part of this, the taxpayer will be invited to make a disclosure using the Contractual Disclosure Facility (CDF). These disclosures are made under Code of Practice 9 (COP9). If managed appropriately, they offer the taxpayer protection against criminal prosecution in exchange for full co-operation.

Alternatively, taxpayers can voluntarily register to make a COP9 disclosure, without the need for an HMRC investigation. As well as immunity from criminal prosecution, this proactive approach can help mitigate penalties.

By agreeing to make a disclosure under COP9, the taxpayer must admit to deliberately committing tax evasion and agree to make a complete and accurate disclosure to HMRC, normally in the form of a report. HMRC can carry out a criminal investigation that could result in prosecution and conviction if the taxpayer refuses an offer to make a disclosure under COP9, or if the process is not suitably managed.

HMRC COP9 investigations are carefully risk assessed before being opened and will often involve a significant tax exposure.

Code of Practice 8

HMRC may undertake an investigation under Code of Practice 8 (COP8) if it believes there is a loss of tax because of complex tax planning or other tax avoidance. Its aim is to establish the facts and recover any tax, interest and penalties due.

If HMRC finds evidence of fraud, it may be escalated either to COP9 or to an investigation under the Police and Criminal Evidence Act 1984.

These investigations can be intrusive, and while HMRC has a duty of taxpayer confidentiality, it may need to request information and documents from third parties (both in the UK and overseas).

HMRC raids

If HMRC suspects that a taxpayer has committed tax evasion, it could order an arrest and/or a raid of a person’s home, other properties or business premises. Taxpayers should immediately seek specialist advice if they face an HMRC raid and should not attempt to stop the search or conceal any documents or materials.

These raids can be worrying, but taxpayers can ask that the search be postponed until their adviser turns up and request a copy of the arrest warrant or investigator’s authorisation. These documents will show what HMRC is and isn’t allowed to review.

How RSM can help

If you receive a letter from HMRC relating to any of the above investigations, our team of tax dispute resolution experts can help. Our team includes chartered tax advisers and fully qualified HM Inspectors of Taxes. We have significant experience in dealing with HMRC investigations co-ordinated by the Fraud Investigation Service and can advise you on what to do through the process.

Please do not hesitate to get in touch with us directly on +44 (0)800 032 8374 or via our dedicated mailbox at