How to tell HMRC about underpaid tax from previous years

Telling HMRC first is almost always the cheapest and safest way out. This guide shows which route to use, what to prepare and how to keep the penalty down.

Choose the right route

Amend a recent Self Assessment return within 12 months of the filing deadline; otherwise use the Digital Disclosure Service, the Worldwide Disclosure Facility for offshore matters, the Let Property Campaign for rent, or COP9 where fraud may be involved.

Notify, then 90 days to disclose and pay

After notification you usually have 90 days to submit year-by-year tax, interest and penalty computations, make an offer and pay, or request Time to Pay.