| A Plus Management Limited | London | 2003 |
| A Plus Medical Services Ltd | Nottingham | 2016 |
| A Plus Skin & Aesthetics Ltd | Glasgow | 2025 |
| A Positive Mind Limited | Leigh On Sea | 2016 |
| A Power Medical Ltd | Merthyr Tydfil | 2023 |
| A Ptak Ltd | Gateshead | 2013 |
| A Pusey Osteopaths Ltd | Haywards Heath | 2024 |
| A Q Locums Limited | Manchester | 2010 |
| A Q Pharma Limited | Bradford | 2018 |
| A Qazi Ltd | Bradford | 2018 |
| A Quality Care Service Limited | Great Chesterford | 2018 |
| A R a Rodriguez Limited | Wimborne | 2023 |
| A R Banerjee Limited | Lutterworth | 2006 |
| A R Brosgill Limited | Harrogate | 2008 |
| A R Cooley Limited | Halesowen | 2008 |
| A R Cornell Limited | Wickford | 1966 |
| A R Doyle Limited | Romsey | 2004 |
| A R Healthcare Agency Ltd | Dagenham | 2018 |
| A R Hygiene Ltd | London | 2026 |
| A R Illidge Ltd | Halsall | 2025 |
| A R K Locums Limited | Nottingham | 2013 |
| A R Kidd Dermatology Services Ltd | Liverpool | 2019 |
| A R Latif Limited | Bedford | 2012 |
| A R Lettington Limited | Bromley | 2024 |
| A R Macfarlane Ltd | Stornway | 2008 |
| A R Machin Limited | Leek | 2019 |
| A R Medical Practitioner Services Limited | Southampton | 2017 |
| A R Medical Services (Cheshire) Limited | Wilmslow | 2019 |
| A R Medics Limited | Lancaster | 2008 |
| A R Meds Limited | Mansfield | 2017 |
| A R Orthotics Ltd | Leicester | 2016 |
| A R PAL ENT Limited | Woodford Green | 2020 |
| A R Payne Ltd | Esher | 2025 |
| A R Pearson Limited | Maidenhead | 2010 |
| A R Podiatry Limited | Enfield | 2025 |
| A R Substance Misuse Limited | London | 2013 |
| A R T Bain Ltd | London | 2021 |
| A Rahman Health Limited | Birmingham | 2026 |
| A Railey Locums Ltd | Birmingham | 2019 |
| A Raja Pharma Ltd | Halifax | 2019 |
| A Ramzan Ltd | Rotherham | 2022 |
| A Rana Consultancy Ltd | London | 2022 |
| A Rashid Medical Ltd | Sale | 2015 |
| A Rasool Limited | Leeds | 2009 |
| A Rated Homecare Ltd | Crowborough | 2018 |
| A Razzaq Ltd | Bradford | 2025 |
| A Reddish Consultancy Ltd | Doncaster | 2018 |
| A Roch Professional Locum Ltd | Harrogate | 2014 |
| A Russell Properties Ltd | Downpatrick | 2022 |
| A S Children & Family Therapy Services Ltd | Loughborough | 2016 |
| A S Dencare Limited | Manchester | 2018 |
| A S Dental Holdings Ltd | Rotherham | 2017 |
| A S F (2010) Limited | Leicester | 2010 |
| A S Hampden Limited | West Harrow | 2015 |
| A S Heer Limited | Coventry | 2021 |
| A S K Healthcare Limited | Manchester | 2018 |
| A S MED Services Ltd | Tilbury | 2016 |
| A S Medical Healthcare Ltd | Manchester | 2013 |
| A S N & Co Limited | Aughton | 2013 |
| A S Paul Limited | Wilmslow | 2011 |
| A S Pharm Limited | Isleworth | 2015 |
| A S R Consultancy Services Limited | Chingford | 2009 |
| A Sabbah Limited | Wolverhampton | 2023 |
| A Sachoo Ltd | Harrow | 2026 |
| A Safe House Limited | Colchester | 2019 |
| A Safe Space With Veena Ltd | Kingston Upon Thames | 2026 |
| A Safer Future Community Interest Company | Norwich | 2025 |
| A Sahal Limited | Sutton Coldfield | 2021 |
| A Sahota Ltd | Lincoln | 2009 |
| A Saidi Ltd | Birmingham | 2022 |
| A Sama Healthcare Ltd | Stevenage | 2019 |
| A Sardar Limited | Huddersfield | 2023 |
| A Scattred Janneh Ltd | Swindon | 2019 |
| A Scottvision Ltd | Sidcup | 2018 |
| A SDT Ltd | Preston | 2022 |
| A Selvin Ltd | Bedford | 2026 |
| A Sereda Limited | Chichester | 2020 |
| A Sethi Ltd | London | 2011 |
| A Shafiq Limited | Morpeth | 2018 |
| A Shaida Ltd | Loughton | 2010 |
| A Sharief Limited | St. Helens | 2024 |
| A Shavit Ltd | Gateshead | 2018 |
| A Siddiqui Consultancy Limited | Leigh-On-Sea | 2019 |
| A Significant Other Limited | Leeds | 2010 |
| A Silva Studio Limited | London | 2013 |
| A Simons (Medical) Limited | Wolverhampton | 2016 |
| A Singh Eyecare Ltd | Manchester | 2026 |
| A Slice of Happiness Innate Health Community Interest Company | Watford | 2024 |
| A Small World Day Nursery Ltd | Cleckheaton | 2018 |
| A Smile for Life Limited | Ilkley | 2008 |
| A Smile Ltd | London | 2018 |
| A Smiles London Ltd | London | 2024 |
| A Soul Full of Community Ltd | Slough | 2024 |
| A Sousa Ltd | Gateshead | 2016 |
| A Space Between C.I.C. | Blaydon-On-Tyne | 2019 |
| A Space to Retreat CIC | Hainault | 2025 |
| A Spark in the Dark Ltd | London | 2021 |
| A Special Design Support Services C.I.C. | Dartford | 2022 |
| A Squared Anaesthetics Limited | Ipswich | 2023 |
| A Squared Healthcare Ltd | London | 2020 |