Many UK small and medium-sized enterprises are failing to properly control how artificial intelligence is used inside their organisations, according to reports. A quarter of UK SMEs said they had identified unauthorised AI tools in use over the past six months. Governance and cost controls are lagging behind rapid adoption, with only a minority reviewing internally built AI under formal documentation. Many firms reported unexpected charges, limited dedicated budgets and difficulty separating AI spending, while few said they can calculate AI return on investment.