Simple tax assessments
HMRC will have the power from 2016-17 to assess an individual’s income tax or capital gains tax liability without them first being required to complete a self-assessment return if HMRC hold enough information (from the individual or a third party) to make the assessment.
Taxpayers will have 60 days to query these, informally. If they are still dissatisfied they will have a further 30 days to appeal formally.
Currently with the informal assessments (P800) being issued for 2015-16 if the taxpayer will not pay any liability shown as due and HMRC have no other means of collection, say through a restriction to a notice of coding, then HMRC have to issue a self-assessment tax return to the individual.