VATMARG03650 | Global accounting: Leaving the global accounting scheme
From HM Revenue & Customs · VAT Margin Schemes
When a business leaves the global accounting scheme - for example, because it deregisters - it must make a closing adjustment. This is because it will have received credit under the scheme for purchases, some of which may not have been sold and may still be in stock.
Details of how the closing adjustment must be made can be found in Notice 718 The Margin Scheme and global accounting.