SAM20080 | Assessments: stand-alone assessments: appeal against an assessment
From HM Revenue & Customs · Self Assessment Manual
A Revenue Assessment is subject to appeal, and you may be required to
record the appeal on the customer’s SA record
stand over all or part of the charge arising from the assessment
amend payments on account for the following year if they have been adjusted following the issue of the assessment
For detailed guidance on handling appeals see SAM10000 and SAM11000 for applications for postponement.