In the TSS portal, when completing supplementary declarations for goods moving from GB to NI, please respond “No” to the question asking if you want to ‘Use Postponed VAT Accounting?’
This question is only relevant if you are importing goods:
- under a customs special procedure
- from the Channel Islands of Jersey and Guernsey (which are considered as ‘Rest of the World’ locations for VAT purposes)
- when goods are subject to an excise duty offset
For further information please read this guidance on gov.uk.