For unquoted shares, shares in private companies that aren’t traded on a recognised exchange, there is no single definitive answer. A valuation is, in effect, an informed and evidence-based opinion, and it needs to be one that HMRC will accept or that can be defended if challenged.
The most commonly used approaches include earnings-based methods (applying a multiple to the company’s maintainable profits), asset-based methods (particularly relevant where a business holds significant property or investments), and dividend yield methods. In practice, the right approach depends on the nature and size of the business, the level of the shareholding being valued, and what the valuation is being used for.
Minority interests, where someone holds less than a controlling stake, will typically attract a discount to reflect the limited influence that comes with a smaller shareholding. The size of that discount is itself a matter of judgement, and one that HMRC’s Shares and Assets Valuations (SAV) team will often want to discuss.