Big H is right. If a car is registered in the north from new even after brexit it isnt liable for vat & duty here, just VRT. That's provided it hasn't been registered in GB in between.
If it has less than 6k km on it or is less than 6 months old it would be classed as new so there would be vat liable.
Also revenue are making changes which could result in a GB car that has been in the north for "a reasonable period of time" no longer liable for vat & duty. What a reasonable amount of time is anybodies guess, but it looks promising.
https://www.revenue.ie/en/vrt/regist...s-from-ni.aspx
Edit: you just beat me to it.
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