The register
The register lists Oak Tree Taxation Ltd in London as a licensed sponsor on Skilled Worker, an entry that goes back to at least 2026. Rating on the current register: Worker (A rating).
At Companies House the business is Oak Tree Taxation Ltd (company number 14993516), a private limited company incorporated in 2023, 3 years ago. Registered office: 71-75 Shelton Street, Covent Garden, London, WC2H 9JQ, WC2H 9JQ. Its filed activity puts it in professional and technical services.
A licence says an organisation may sponsor; it does not say it is hiring today. The way to find out is the same as for any employer: the careers page, the job boards, and a direct approach with a UK-style CV that says early that sponsorship would be needed.