The register
The register lists A2B TAX LTD in London 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).
At Companies House the business is A2B TAX LTD (company number 13198940), a private limited company incorporated in 2021, 5 years ago. The registered office is at 133 Creek Road, London, SE8 3BU, SE8 3BU. By its SIC codes the business is in professional and technical services.
Holding a licence is the expensive, slow part done. For A2B TAX LTD the question each time is only whether the role and the pay fit the current rules, and that is checked per vacancy.