Stand-alone assessments which are generally referred to as Revenue Assessments, will only will be required in specific circumstances. Self-assessment customers are required to self assess and any amendment to their self-assessment will be made by either the customer or HMRC, so a stand-alone assessment won't normally be required.
A stand-alone assessment is not a self-assessment and exists apart from a self assessment. A stand-alone assessment is, however, a further assessment to any self-assessment that has been made by the customer. If there is no self-assessment, for example because there is a failure to notify chargeability, a stand-alone assessment is not a further assessment.
If an original stand-alone assessment is discovered to be insufficient a further assessment should be made.
From 6 April 1998 the charge arising from all new assessments, and further assessments (other than Special Assessments and simple assessments), will be recorded onto the customer's SA record. This is so the Section 86 TMA1970 (up to 30 October 2011) and FA2009 Section 101 and Schedule 53 (from 31 October 2011) interest provisions are handled correctly.