Hi @thebluehound ,
Hyde here from Shopify. Great question!
Brexit has been disruptive in many respects and has required significant adaptation, not least of all in terms of shipping and tax. We do have a guide about UK taxes and Brexit right here, and the closest approximation to an answer to your question is provided here:
Yet the truth is that our document is far from comprehensive, so in order to get the most definitive answers you would need to contact your local tax authority.
I hope this helps!
All the best, Hyde.