| AG Fire Sprinklers Ltd | Oldham | 2018 |
| AG Gibbs (2021) Ltd | Stroud | 2021 |
| AG Sarpong Limited | Croydon | 2022 |
| AGA Fire Consultancy Ltd | Poulton-Le-Fylde | 2016 |
| AGA Firestopping Ltd | Stevenage | 2025 |
| Agad Health Care Ltd | Birmingham | 2022 |
| Agap Healthcare Ltd | Hornchurch | 2019 |
| Agathos Care Services Limited | Chesterfield | 2024 |
| Agbabola Limited | Sunderland | 2025 |
| Agcmhealth Limited | Southsea | 2019 |
| Agdee Limited | Manchester | 2023 |
| Agile Regulatory Limited | Braintree | 2021 |
| AGM Health Care Services Limited | Walsall | 2022 |
| Agma Services Limited | Sheffield | 2019 |
| Agnspire Care Ltd | Peterborough | 2024 |
| AGO Compliance Limited | Colchester | 2020 |
| AGO Fire and Rescue Limited | Elmstead Market | 2022 |
| AGO Safety Services Limited | Colchester | 2013 |
| Agonabrothers Limited | Colchester | 2025 |
| Agro Security Services Limited | Belfast | 2022 |
| AGS Security Management Ltd | Banbury | 2007 |
| AH Clinipro Ltd | Congleton | 2021 |
| Ah-Healthcare Services Ltd | Liverpool | 2021 |
| Ahbidi Ltd | London | 2020 |
| Ahprocess Ltd | Winchester | 2023 |
| AI Health and Safety Ltd | Northampton | 2025 |
| AI Healthcare UK Academy Ltd | Carshalton | 2023 |
| AI Homecare Group Ltd | Saintfield | 2019 |
| Ai-Win Care Limited | London | 2022 |
| AIA Wallop Defence Ltd | Fareham | 2024 |
| Aiglemd Limited | Manchester | 2022 |
| Aikuchem Services Limited | Birmingham | 2023 |
| AIM Defence Ltd | London | 2025 |
| Air Health and Wellbeing Limited | Loughton | 2024 |
| Air Safety Support International Limited | Crawley | 2000 |
| Airaa Swaan Ltd | Bury St. Edmunds | 2024 |
| Airbus Defence Limited | Newport | 2026 |
| Aire Valley Fire Ltd | Leeds | 2026 |
| Airosafe Ltd | Weymouth | 2019 |
| Airsoft Defence Ltd | Leicester | 2026 |
| Airwaves-Pfp Ltd | Chesterfield | 2020 |
| Aisha Khan Limited | Glasgow | 2017 |
| Aisha M Healthcare Limited | London | 2021 |
| Aitiven Ltd | Manchester | 2021 |
| Aitken Engineering Ltd | London | 2023 |
| Aiva Health Clinic & Phlebotomy Training Services Ltd | Harrow | 2024 |
| AJ Fire Protection Limited | Nottingham | 2023 |
| AJ National Fire Limited | Knutsford | 2019 |
| AJA Consulting International Ltd | London | 2026 |
| Ajanta Social Care Limited | Birmingham | 2017 |
| Ajax Resource TM Ltd | Blyth | 2023 |
| AJD Contracting Ltd | Hove | 2019 |
| AJL Audit Ltd | Wetherby | 2026 |
| AJL QS Ltd | London | 2023 |
| AJM Fire Safety Limited | Wolverhampton | 2019 |
| AJN Fire Safety Ltd | Maidstone | 2019 |
| AJS Admin Limited | Bournemouth | 2025 |
| Ajsafety Ltd | Runcorn | 2025 |
| AK Fire and Safety Ltd | Preston | 2018 |
| AK Fire Safety Ltd | Northampton | 2023 |
| AK Quality Solutions Ltd | Rowlands Gill | 2019 |
| Akani Ltd | London | 2013 |
| Akbar DAD Ltd | Leeds | 2016 |
| AKC Opportunities Foundation CIC | Sidcup | 2025 |
| Akdbj Limited | Westbury | 2020 |
| Akej Limited | Leicester | 2026 |
| Akin & PP Limited | Manchester | 2023 |
| Akkr Partners Limited | Huddersfield | 2024 |
| Akons and Sons Limited Limited | Harlow | 2020 |
| AKS Fire Safety Limited | Solihull | 2014 |
| AKW Consulting (H&S) Ltd | Telford | 2023 |
| Akwascare Ltd | Dartford | 2019 |
| Akwasidae UK Limited | London | 2025 |
| AL Sihiya Limited | Wilmslow | 2025 |
| Al-Munawwarah Educational & Cultural (UK) | Coventry | 2026 |
| Al-Zahra Education Limited | Chadwell Heath | 2013 |
| Alaina Louise Ltd | Hove | 2021 |
| Alamarr Limited | Lisburn | 2021 |
| Alan T Morrall Ltd | Doncaster | 2022 |
| Alara J Ltd | Coventry | 2026 |
| Alas Education Limited | London | 2023 |
| Albany Communication Trust Limited | Bath | 2007 |
| Albertchicom Ltd | London | 2026 |
| Albion Fire Solution Ltd | East Brent | 2025 |
| Albodross Ltd | Maidstone | 2019 |
| ALC Fire Solutions Ltd | Hereford | 2021 |
| Alchemy by Effect Doctors Limited | Burgess Hill | 2019 |
| Alcis Holdings Limited | Guildford | 2004 |
| Alcomb Care Limited | Alton | 2025 |
| Alcon Health Ltd | Basildon | 2019 |
| Alden Fittings Limited | Stanmore | 2001 |
| Alder Healthcare Ltd | London | 2024 |
| Aldgate Fire Commercial Ltd | Chobham | 2025 |
| Aleherb Care Limited | Uxbridge | 2021 |
| Alemika Ltd | London | 2026 |
| Alemily Health Ltd | London | 2019 |
| Alert Fire Safety Services Limited | Wellingborough | 2020 |
| Alexander Mandeville Construction Limited | Braintree | 2014 |
| Alexander Rose Consultancy Ltd | Hereford | 2025 |
| Alexander Surveying Services Limited | London | 2017 |