How to test a UK business idea before you register a company
You can learn whether an idea has demand without incorporating. The register will not see a weekend stall.
Registering a limited company is easy. Learning whether anyone will pay you is not.
Companies House can show how many live companies share a SIC and how many have never filed. It cannot show typical sales, and it cannot see sole traders.
A cheaper test is a capped experiment: a weekend stall, prepaid pop-up, or twenty priced conversations. Keep the receipts.
Sources: Companies House live register; electronic accounts product; GOV.UK set up a limited company.