| ACT &More Limited | Hartlepool | 2018 |
| ACT Activity Camps Limited | East Grinstead | 2019 |
| ACT Care Service Ltd | Birmingham | 2023 |
| ACT Counselling and Training Services Ltd | Glasgow | 2023 |
| ACT for Yorkshire Ltd | Leeds | 2011 |
| ACT Glow UP Ltd | London | 2025 |
| ACT Locums Ltd | Bradford | 2026 |
| ACT Medics Ltd | Woolwich | 2015 |
| ACT NOW Medical Limited | Lynmouth | 2024 |
| ACT of Care Ltd | London | 2023 |
| ACT Pharma Consulting Limited | Lytham St Annes | 2015 |
| ACT Pharma Limited | Bolton | 2022 |
| Acta Homes Ltd | Watford | 2024 |
| Actenow Ltd | London | 2021 |
| Acterial PVT Ltd | Doncaster | 2018 |
| Acti-Mind Neurodiverse CIC | Nottingham | 2026 |
| Actif Recovery Limited | Bronwydd Arms | 2025 |
| Actikid Ltd | Edgware | 2015 |
| Acting to Revive Care Limited | Birmingham | 2025 |
| Action 2 Care Ltd | Wellingborough | 2015 |
| Action 4 Support CIC | Newbridge | 2018 |
| Action Against Cancer Limited | Bury | 2015 |
| Action Against Food Poverty CIC | Colchester | 2026 |
| Action Against Hunger UK | London | 1995 |
| Action Against Medical Accidents | London | 1988 |
| Action Around Bethlehem Children With Disability | Andover | 2002 |
| Action Breaks Silence Ltd | Wembley | 2013 |
| Action Business Builder Limited | Orpington | 2008 |
| Action Cancer | Belfast | 1985 |
| Action Care & Support Ltd | Leeds | 2026 |
| Action Disability Kensington & Chelsea | London | 1995 |
| Action Disability Swindon | Swindon | 2010 |
| Action Duchenne Limited | Bristol | 2003 |
| Action East Devon Ltd | Ottery St. Mary | 2009 |
| Action First Physiotherapy Limited | Goole | 2016 |
| Action for Blind People | London | 1888 |
| Action for Care Limited | Chesterfield | 2008 |
| Action for Carers (Surrey) | Burpham Guildford | 2006 |
| Action for Children | Watford | 2003 |
| Action for Children (Northern Ireland) Ltd | Belfast | 2016 |
| Action for Children (Scotland) Ltd | Glasgow | 2016 |
| Action for Children (Wales) Ltd | Cardiff | 2016 |
| Action for Children Developments Limited | Watford | 2009 |
| Action for Children Services Limited | Watford | 1989 |
| Action for Deafness | Haywards Heath | 2007 |
| Action for Elders Trust | Cardiff | 2011 |
| Action for Elders UK C.I.C. | Swansea | 2011 |
| Action for Family Carers | Maldon | 2008 |
| Action for Happiness | London | 2017 |
| Action for Harmony Ltd | Alperton | 2023 |
| Action for Life Training Limited | Exmouth | 2023 |
| Action for M.E. | Bristol | 1994 |
| Action for Sport | Bingley | 2019 |
| Action for Stammering Children | London | 1988 |
| Action Greater Bedminster Community Interest Company | Bristol | 2025 |
| Action Heart (Trading) Limited | Dudley | 1990 |
| Action Homecare Ltd | Spalding, | 2024 |
| Action House Childcare Limited | Dorking | 2018 |
| Action in Mind | Stirlingshire | 1994 |
| Action International Ministries (UK) | Birmingham | 1996 |
| Action Isleworth Mothers (AIM) Ltd | Isleworth | 2023 |
| Action Medical Services Limited | Borehamwood | 2013 |
| Action Medics Limited | Richmond | 2019 |
| Action on Addiction | Wiltshire | 2006 |
| Action on Asbestos | Glasgow | 2011 |
| Action on Disability | North Fulham | 2001 |
| Action on Disability and Development | Frome | 1986 |
| Action on Gilbert's Syndrome | Bedford | 2003 |
| Action on Pre-Eclampsia Limited | Evesham | 1992 |
| Action on Smoking and Health | London | 1971 |
| Action on Smoking and Health (Scotland) | Edinburgh | 1992 |
| Action on Substances Through Community Education and Related Training (Ascert) | | 2006 |
| Action Physiotherapy Ltd | Leighton Buzzard | 2006 |
| Action Plan Care Ltd | London | 2020 |
| Action Point Community Support Services | Keighley | 2001 |
| Action Relief | London | 2017 |
| Action Station South Tyneside Limited | South Shields | 1998 |
| Action Village India | London | 2007 |
| Action Vision Zero C.I.C. | London | 2020 |
| ACTION18 Healthcare Ltd | Manchester | 2018 |
| ACTION24 Healthcare Ltd | Southampton | 2023 |
| ACTION4ACCESS Ltd | Harrogate | 2026 |
| Actionphysio Limited | Coventry | 2006 |
| Actions for Community Development Limited | London | 2009 |
| Actions-Plans Limited | London | 2014 |
| ACTIONS4U Care Ltd | Norwich | 2023 |
| Actis Medical UK Limited | Richmond Upon Thames | 2025 |
| Activ Camps Limited | London | 2019 |
| Activ Physiotherapy Ltd | Sheffield | 2012 |
| ACTIV8 Camps Ltd | York | 2024 |
| ACTIV8 Nursery Henfield Limited | Worthing | 2018 |
| ACTIV8 Rehab Limited | Reading | 2004 |
| ACTIV8 Wellbeing Limited | Liversedge | 2020 |
| ACTIV8-N-CREA8 Youth Project | London | 2012 |
| ACTIV8U Limited | Woking | 2016 |
| Activa Medical Ltd | London | 2025 |
| Activate Care Ltd | Birmingham | 2024 |
| Activate Clinical Research Ltd | Coventry | 2024 |
| Activate Medicals Limited | Bradford | 2023 |
| Activate Northants Ltd | Kettering | 2023 |