BIM31515 | Value Added Tax: turnover below registration threshold

From HM Revenue & Customs · Business Income Manual

A trader whose taxable turnover does not exceed a specified registration threshold (`the VAT registration threshold’) does not need to register as a taxable person but may do so if they wish.

However, if the trader wishes to register they must satisfy HMRC that they make or intend to make taxable supplies in the course or furtherance their business.

The VAT registration threshold is subject to alteration. It is prescribed in and is amended by statutory instrument, usually annually.