The register
The register lists 4base Construction Ltd in Southall as a licensed sponsor on Skilled Worker, an entry that goes back to at least 2026. Its rating on the register is Worker (A rating).
4base Construction Ltd is the registered name (Companies House number 09213424), a private limited company on the register since 2014. Registered office: 6 Turing Court, Lovell Road, Southall, UB1 3EX, UB1 3EX. Its filed activity puts it in construction.
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.