The register
The register lists CoStar UK Limited in London as a licensed sponsor on Skilled Worker and Global Business Mobility: Senior or Specialist Worker, 2 routes in all, and has done since at least 2026. Its rating on the register is Worker (A rating).
Costar UK Limited is the registered name (Companies House number 01789170), a private limited company on the register since 1984. The registered office is at C/O Csc Cls (Uk) Limited 5 Churchill Place, 10th Floor, London, E14 5HU, E14 5HU. By its SIC codes the business is in it, software and media. It has traded under other names before, including Focus Information Limited, Property Intelligence Limited.
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.