VATF34400 | What to consider prior to determining whether to use an intervention: applying VAT basics: did the supply take place in the UK?

From HM Revenue & Customs · VAT Fraud

Once you have determined whether there has been a supply of goods or services the place of supply needs to be confirmed. Guidance on place of supply can be found at:

VATPOSG for goods,
VATPOSS for services, and
VATPOSTR for transport.

After determining whether the supply was made in the UK the next step is to look at whether the supply was made by a taxable person.