How far back can HMRC assess under-declared taxes?

From income tax to VAT, HMRC has specific time limits for issuing tax assessments. Depending on the circumstances—whether it’s standard, careless, offshore, or deliberate behaviour—these limits can stretch from 4 to 20 years.

HMRC’s time limits apply in different ways to various taxes, including income tax, capital gains tax, corporation tax, VAT, insurance premium tax, aggregates levy, climate change levy, landfill tax, inheritance tax, stamp duty land tax, stamp duty reserve tax, petroleum revenue tax, and excise duty.

There are four time limits within which assessments can be issued. These are:

• 4 years from the end of the relevant tax period
• 6 years (careless) from the end of the relevant tax period
• 12 years (offshore) from the end of the relevant tax period
• 20 years (deliberate) from the end of the relevant tax period

The 4-year time limit is the standard time limit for all taxes.

The 6-year time limit applies when taxes have been lost due to the careless behaviour of the taxpayer, or another person acting on their behalf.

The 12-year time limit applies when taxes have been lost due to an offshore matter or offshore transfer. This also applies if reasonable care was taken, or the behaviour is considered careless by the taxpayer or another person acting on their behalf.

Lastly, the 20-year time limit applies when taxes have been lost due to the deliberate behaviour of the taxpayer or another person acting on their behalf, or if the taxpayer has failed to comply with specific historic obligations for periods ending before 1 April 2010.