Welcome to the Community, @shabbington.
I can help get the support you need in QuickBooks Online. To determine if there's a need for you to register as VAT, it would be best to consult HMRC or an accounting professional for more information and guidance.
In case you need the direct link to the website, check this out: Contact HMRC - GOV.UK.
In the meantime, you can check the following article for some links about VAT:
Please leave a comment below if you have any other concerns. I'm always around to help. Wishing you a good one.