| ABU AL Khalil Welfare CIC | Middlesbrough | 2024 |
| ABU Hannah Limited | Birmingham | 2025 |
| Abundantly Blessed Ltd | Reading | 2022 |
| Abutment Healthcare Limited | London | 2022 |
| AC Consultant (London) Limited | Caterham On The Hill | 2011 |
| AC Psychology Ltd | Newcastle Upon Tyne | 2020 |
| ACA Health & Safety Services Ltd | Ipswich | 2019 |
| ACA Health Care Services Ltd | Aldershot | 2018 |
| Acacia Dales Services Ltd | Preston | 2023 |
| Academe Trainers | Nuneaton | 2021 |
| Academic Ants Ltd | Cardiff | 2025 |
| Academy for Sickle Cell and Thalassaemia (Ascat) Ltd | Herts | 2023 |
| Academy of Traditional Japanese Karate Ltd | Hinckley | 2025 |
| Acanthus Fire Safety Consultancy Limited | Bury St Edmunds | 2022 |
| ACB Fire Sprinklers Limited | Ashford | 2022 |
| ACC Care Group Ltd | Cambridge | 2025 |
| Accad Healthcare Limited | London | 2021 |
| Access 24/7 Care Ltd | Craigavon | 2025 |
| Access SWS Ltd | London | 2025 |
| Accesslink Health CIC | Sittingbourne | 2026 |
| Accident Prevention&Control Ltd | London | 2025 |
| Acclaim Care Agency Limited | Milton Keynes | 2023 |
| Accord Living Limited | Birmingham | 2018 |
| Accordon Limited | London | 2021 |
| Accurate Care Limited | Southampton | 2023 |
| Accurate Fire Solutions Ltd | Maidstone | 2020 |
| Accurate Healthcare Ltd | Mitcham | 2016 |
| Ace Alarms Limited | Westgate-On-Sea | 2021 |
| Ace Fencing & Paving Limited | Chorley | 2021 |
| Ace Fire Group Limited | Billericay | 2002 |
| Ace Fire Protection Limited | Billericay | 1995 |
| Ace Love Ltd | Doncaster | 2023 |
| Ace Personal Safety Awareness & Nutrition Ltd | Cardiff | 2019 |
| Ace Therapeutic Care Ltd | Lincoln | 2025 |
| Ace Your Life Coaching Ltd | Dorchester | 2024 |
| Acebes Livelo Ltd | Pinner | 2024 |
| Acer Fire Protection Limited | Rochester | 2023 |
| ACG Fire Protection Limited | Oldham | 2021 |
| Achievers Educational Support Services Limited | Wellingborough | 2024 |
| Achieving for Children Community Interest Company | Twickenham | 2014 |
| Achieving Real Change in Communities CIC | Newcastle Upon Tyne | 2014 |
| Achieving, Encouraging, Inspiring CIC | Bristol | 2023 |
| Ackal Ltd | Bury | 2026 |
| Aclr & Daughters Ltd | Wallington | 2024 |
| Acme Fire Protection Ltd | Essex, | 2025 |
| Acorn Fertility Ltd | Croydon | 2022 |
| Acorn Fire & Security Ltd | Blackburn | 2002 |
| Acorn Fire Protection Ltd | Horsham | 2026 |
| Acott Fire Scene Investigations Limited | Alton | 2013 |
| ACP Health Care Limited | Milton Keynes | 2022 |
| Acreditsafe Limited | Chelmsford | 2023 |
| Across Ummah CIC | Manchester | 2022 |
| ACS Advisory Limited | Edinburgh | 2016 |
| ACS UK IT Consulting Ltd | Leicester | 2018 |
| ACT Care Support Limited | Leamington Spa | 2022 |
| ACT Child Care Services Limited | Leamington Spa | 2025 |
| ACT on Care Ltd | Birmingham | 2018 |
| ACT on IT Therapies Ltd | London | 2025 |
| Actifire Limited | Sutton In Ashfield | 2023 |
| Action 4 Kenyan Street Kids Limited | London | 2025 |
| Action Care Limited | Oldbury | 2021 |
| Action on Climate in Teignbridge CIC | Teignmouth | 2019 |
| Activate OT Hampshire Ltd | Romsey | 2023 |
| Active 8 Support Services Limited | Liverpool | 2006 |
| Active Care Connect Ltd | Sidcup | 2026 |
| Active CARE24 Ltd | Coventry | 2021 |
| Active Fire Management Limited | East Sussex | 2001 |
| Active Fire Safety Limited | Tring | 1998 |
| Active Fire Safety Solutions Ltd | Derby | 2019 |
| Active Fire Solutions Limited | Ashford | 2010 |
| Active Fire UK Ltd | Sidcup | 2023 |
| Active Minds Pontefract Ltd | Pontefract | 2021 |
| Active Security Solutions Limited | Wolverhampton | 2008 |
| Activfire Ltd | Romford | 2015 |
| Activsafety Ltd | London | 2019 |
| Actualized ME Ltd. | Birmingham | 2021 |
| Actus Health & Safety Ltd | Sheffield | 2020 |
| Acuity Digital Intelligence Ltd | London | 2026 |
| Acumen Safety Limited | Sheffield | 2018 |
| Acupuncture and Herbs Clinic Ltd | Smethwick | 2026 |
| Acupuncture Regulatory Authority Ltd | Macclesfield | 2022 |
| Acuronholdings Ltd | Edinburgh | 2021 |
| AD (Southern) Fire Limited | Southampton | 2025 |
| Adam Healthcare & Wellbeing Ltd | Chelmsford | 2025 |
| Adam Mahmood Ltd | Sheffield | 2022 |
| Adams Care Living Ltd | London | 2024 |
| Adams Care SL Ltd | Batley | 2020 |
| Adaptive Device Solutions Ltd | Doncaster | 2019 |
| Adara Fire Safety Consultancy Ltd | Sudbury | 2025 |
| Adash Healthcare Limited | Kingston Bagpuize | 2022 |
| Adashe Fire Ltd | Surbiton | 2025 |
| ADB Management Services Limited | Bromsgrove | 2018 |
| ADB Tech Ltd | Cheltenham | 2024 |
| Adco Fire and Safety Limited | Glasgow | 2017 |
| ADD Fire Solutions Limited | Birmingham | 2022 |
| Addcare Ltd | Coventry | 2021 |
| Addiction Lifeline Ltd | Southend-On-Sea | 2021 |
| Addilyn Group Limited | London | 2017 |
| Addoc Health Care Ltd | Bedford | 2018 |
| Addonohue Ltd | Doncaster | 2023 |