What triggers an HMRC tax investigation?

HMRC uses Connect software to cross-reference data from banks, employers, SDLT, DVLA, and more. Common triggers: undeclared income, large discrepancies between income and assets, rental income not declared, offshore accounts.

What are the HMRC penalty ranges?

For inaccuracies: careless 0–30% (unprompted) or 15–30% (prompted). Deliberate (not concealed) 20–70% or 35–70%. Deliberate and concealed 30–100% or 50–100%. Higher rates for offshore failures.

What is Code of Practice 9 (COP 9)?

COP9 is HMRCs procedure for suspected serious tax fraud. You are offered a Contractual Disclosure Facility (CDF) — disclose everything and get immunity from prosecution; refuse and risk criminal investigation.

UK HMRC Tax Investigation Risk & Penalty Calculator

Assess HMRC tax investigation risk and calculate potential penalties. Penalty ranges: unprompted disclosure 15–30%, prompted 30–70%, deliberate 50–100% (offshore 200%). Includes COP 9 procedure overview.

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$ Finance Disclaimer: These calculators are for educational and illustrative purposes only. Results do not constitute financial advice. Consult a licensed financial advisor before making investment or borrowing decisions.

How to Use

Enter the values for the scenario you are assessing. Assess HMRC tax investigation risk and calculate potential penalties. Penalty ranges: unprompted disclosure 15–30%, prompted 30–70%, deliberate 50–100% (offshore 200%). Includes COP 9 procedure overview. Use the uk tax investigation risk result to inform your calculation.

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Frequently Asked Questions

What triggers an HMRC tax investigation?

What are the HMRC penalty ranges?

What is Code of Practice 9 (COP 9)?