The register
The register lists Smartbook Accountancy Ltd in Rainham as a licensed sponsor on Skilled Worker, an entry that goes back to at least 2026. Rating on the current register: Worker (A rating).
Companies House lists it as Smartbook Accountancy Ltd, number 08854495, incorporated 2014: 12 years of filings behind the name. The registered office is at 31 Grangewood Avenue, Rainham, RM13 9PA, RM13 9PA. Its filed activity puts it in professional and technical services. It has traded under other names before, including Taxassist Direct (ldn) Ltd.
Holding a licence is the expensive, slow part done. For Smartbook Accountancy Ltd the question each time is only whether the role and the pay fit the current rules, and that is checked per vacancy.