The register
The register lists GEM Environmental Building Services Ltd in London, Camden as a licensed sponsor on Skilled Worker, an entry that goes back to at least 2026. Rating on the current register: Worker (A rating).
Gem Environmental Building Services Limited is the registered name (Companies House number 03893436), a private limited company on the register since 1999. The registered office is at 130 Shaftesbury Avenue, 2nd Floor, London, W1D 5EU, W1D 5EU. By its SIC codes the business is in it, software and media. It has traded under other names before, including P & S Plumbing 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.