The register
The register lists Lantum 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 Lantum Ltd (company number 07529895), a private limited company incorporated in 2011, 15 years ago. The registered office is at 1 Mark Square, 4th Floor, London, EC2A 4EG, EC2A 4EG. By its SIC codes the business is in it, software and media. It has traded under other names before, including Network Locum Ltd.
What the licence tells a candidate is that the door is not locked. Whether it is open this month is a question for Lantum Ltd's own careers page and the job boards, and the answer changes with the season and the order book.