I just got off the phone with crossborderit and it sounds like a good option:
19.99€ per month + 1€ per order, they handle registration and tax reports. At the moment, the one drawback is that you need to send daily reports to them on your EU sales (if you had any that day). So basically right now they are not integrated with shopify nor do they need to be, however, they do have a Shopify app in BETA which they said will be ready in a few months, which will streamline everything and remove the need for manual daily reporting. For those of us who don’t sell a huge amount to the EU this sounds like a great option - I’m going to give it a go. And Shopify as someone else mentioned, it’s not only the UK being affected by this - it’s anyone outside of the EU.