| A.A.S. Medical Services Limited | Norwich | 2025 |
| A.Abdullahi Ltd | London | 2022 |
| A.Afr Ltd | Belfast | 2025 |
| A.Akbar Medical Services Ltd | Great Yarmouth | 2025 |
| A.Arshad Locum Ltd | Walsall | 2025 |
| A.B Diagnostic Ultrasound Imaging Limited | London | 2023 |
| A.B SLT Limited | Northfleet | 2025 |
| A.B. Health Limited | Durham | 2009 |
| A.B. Medical Services Limited | Southampton | 2003 |
| A.B.C Paramedic Services Ltd. | Newbridge | 2012 |
| A.Banerjee Dermatological Services Limited | Birmingham | 2014 |
| A.Bellaries Limited | Ripon | 2012 |
| A.Berry Support Services Limited | Denby | 2016 |
| A.Bhat Medical Limited | Lancashire | 2025 |
| A.Bridgeman Ltd | Leeds | 2024 |
| A.C Medical Group N.I Ltd | Lurgan | 2023 |
| A.C Sika Limited | London | 2015 |
| A.C. Diagnostics Ltd | Glasgow | 2019 |
| A.C. Moule Limited | Middlesbrough | 2015 |
| A.C. Smile Project Ltd | London | 2026 |
| A.C.C.E.S.S 2016 Limited | Sutton-In-Ashfield | 2016 |
| A.C.E Interventions Ltd | Whitley Bay | 2020 |
| A.C.E Supporting Services Limited | Ayr | 2024 |
| A.C.E-Caring Ltd | Wolverhampton | 2023 |
| A.C.H. (Medical Legal) Limited | Sheffield | 2010 |
| A.C.H. (Yorkshire) Limited | Sheffield | 2010 |
| A.C.O.R.D (Agency for Co-Operation and Research in Development/Association DE Cooperation ET DE Recherche Pour LE Developpement) | London | 1981 |
| A.C.T Healthcare Limited | Torquay | 2012 |
| A.C.T. Healthcare and Training Services PVT Ltd | Taunton | 2014 |
| A.D Assessments Limited | Colchester | 2021 |
| A.D. Adeyemo Limited | Hereford | 2010 |
| A.D. Jacob Limited | Manchester | 2010 |
| A.D.I. Scotland Ltd | Edinburgh | 2012 |
| A.Dubb Optics Ltd | Birmingham | 2025 |
| A.E Locums Ltd | Birmingham | 2015 |
| A.E.N. Limited | Wilkieston Kirknewton | 2003 |
| A.E.Pharma Limited | Chester | 2009 |
| A.F. Clough Dental Care Limited | Old Harlow | 2011 |
| A.F. Clough Limited | Old Harlow | 2007 |
| A.F. Clough Ortho Ltd | Harlow | 2024 |
| A.F.S.N Services Ltd | London | 2022 |
| A.Folashade Ltd | Newcastle Upon Tyne | 2025 |
| A.G Dentistry Ltd | Ellesmere Port | 2024 |
| A.G Foundation Ltd | London | 2021 |
| A.G Perrott Independent Social Work Ltd | Huddersfield | 2024 |
| A.G. Lowrie Limited | Dundee | 2014 |
| A.G.E. Nursing Homes Limited | Essex | 1990 |
| A.G.Wade Ltd | Cardiff | 2003 |
| A.H Dent Ltd | Altrincham | 2022 |
| A.H Independent Consultant Limited | Colchester | 2019 |
| A.H.Allam ENT Limited | Ellesmere Port | 2020 |
| A.H.G.C Services Ltd | Epping | 2022 |
| A.H.T. Care Ltd | Rochdale | 2022 |
| A.H.Taqui Limited | Huddersfield | 2014 |
| A.H.Walker Cardiac Surgeon Limited | Sheffield | 2019 |
| A.I. (Edinburgh) Limited | Glasgow | 2018 |
| A.I. (North) Limited | Glasgow | 2018 |
| A.I. Care Services Ltd | London | 2016 |
| A.I.D. Healthcare Ltd | Glasgow | 2026 |
| A.I.I Healthcare Ltd | Harlow | 2025 |
| A.I.K Optics Ltd | Huddersfield | 2022 |
| A.I.M Enterprises 2025 Limited | Liverpool | 2025 |
| A.I.M. High Project CIC | London | 2017 |
| A.I.M.(Care) Limited | London | 2009 |
| A.I.S. Physiotherapy Services Limited | Cardiff | 2002 |
| A.J Orthodontics Limited | Northwich | 2007 |
| A.J Smartchoice Ltd | Sunderland | 2022 |
| A.J. Hamer Limited | Sheffield | 2009 |
| A.J. Henderson Ltd | Cockermouth | 2024 |
| A.J. Independent Social Work Services Limited | London | 2025 |
| A.J. Lees Medical Limited | London | 2010 |
| A.J. Nuttall Limited | Rochdale | 1994 |
| A.J. Quyn Ltd | Leeds | 2019 |
| A.J.A Pharmaceuticals Limited | Rochdale | 2025 |
| A.J.E Care Services Ltd | Welling | 2025 |
| A.JF2 Profits Limited | London | 2014 |
| A.Johal Optics Ltd | Nottingham | 2015 |
| A.K Aesthetics Ltd | Staines-Upon-Thames | 2024 |
| A.K DEN Ltd | Manchester | 2025 |
| A.K Health Group Ltd | Pinner | 2026 |
| A.K. Medical Ventures Limited | Benfleet | 2015 |
| A.K.Haleath Consultant Limited | Walsall | 2010 |
| A.Karwani Services Ltd | Acton | 2018 |
| A.L.I Ultrasound Limited | Ashford | 2016 |
| A.L.O. Physiotherapy Clinic Ltd | London | 2004 |
| A.L.P Care & Support CYF | Newport | 2020 |
| A.Leader Ltd. | London | 2024 |
| A.M Laser Studio Limited | Leyland | 2026 |
| A.M Medical Group Limited | London | 2025 |
| A.M. Eminence Ltd | Enfield | 2015 |
| A.M. Health Collective Ltd | London | 2026 |
| A.M. Independent Assessments Limited | Barnet | 2014 |
| A.M. Sonography Ltd | London | 2023 |
| A.M.C GDP Ltd | Altrincham | 2022 |
| A.M.D Care Company (UK) Limited | East Grinstead | 2016 |
| A.M.E Medical Ltd | London | 2020 |
| A.M.H Dental Innovations Limited | Ellesmere Port | 2022 |
| A.M.M. Counselling & Psychotherapy Ltd | High Barnet | 2020 |
| A.M.Maramba Ltd | Coventry | 2012 |
| A.M.P.T. Limited | Blackburn | 2018 |