Practical advice on the extended time limits for assessments on offshore income and gains from Tolley Guidance

From 2019 HMRC will have 12 years to raise assessments on offshore matters even if the taxpayer has made an innocent error. This will catch years back to 2013-14 if the taxpayer has been careless or 2015-16 if they made a mistake despite taking reasonable care.

On 6 July 2018 draft legislation (tinyurl.com/HMRC-3659) was published for inclusion in Finance Bill 2019 to extend the tax assessment time limit (during which HMRC may investigate non-compliance and issue notices of determination) to 12 years 
in cases of mistakes or non-deliberate errors involving offshore income capital gains or chargeable transfers.

Currently the time limit for HMRC to make an assessment to income tax and capital gains tax if the taxpayer took reasonable care is four years from the end of the tax year (six years for careless behaviour and 20 years for deliberate behaviour ...