The COP9 investigation process
Once HMRC has issued COP9 to you, you automatically receive immunity from prosecution for the tax offence.
If you do not respond to the CDF offer, or their outline disclosure is invalid, HMRC will treat this as rejecting the CDF offer. HMRC could then commence either a civil or a criminal investigation into the tax fraud they suspect of being committed.
When the nature and extent of the tax fraud is straightforward, it may be possible to conclude the CDF without preparing a formal disclosure report. However in more complex cases, a report will be required to explain and support how the fraud has been committed.
The CDF route may also be appropriate in cases of voluntary disclosures of tax fraud.