| AL Barron Limited | Information & communication | 2024 |
| Alan Bond Photography Limited | Professional & scientific | 2003 |
| Alan Joy Properties Limited | Real estate | 2006 |
| Alchemy Performance Development Ltd | Financial services | 2023 |
| Alcor Data Services Ltd | Information & communication | 2015 |
| Alderley Land Limited | Agriculture & fishing | 1997 |
| Alderley Property (Chippenham) Limited | Real estate | 2020 |
| Aldun Ltd | Real estate | 2021 |
| Alem Holdings Limited | Financial services | 2019 |
| Alem Nightlife Limited | Arts & recreation | 2016 |
| Alem Property Developments Ltd | Real estate | 2016 |
| Alex Carter Coaching Ltd | Hospitality | 2023 |
| Alex Carter Enterprises Ltd | Education | 2021 |
| Alfa&Omega Ltd | Health & social care | 2023 |
| Alford Property Limited | Real estate | 2024 |
| ALH Designs Ltd | Wholesale & retail | 2024 |
| ALH Psychology Ltd | Education | 2023 |
| Alias Studios Ltd | Information & communication | 2023 |
| Alice Ives Limited | Professional & scientific | 2018 |
| Alicia Hawker Eventing Ltd | Arts & recreation | 2023 |
| Alison Edgar Ltd | Administrative & support | 2020 |
| ALL About Action Ltd | Administrative & support | 2025 |
| ALL About Communication Limited | Professional & scientific | 2006 |
| ALL Boxed Limited | Administrative & support | 2014 |
| ALL Eyes and Ears Ltd | Information & communication | 2018 |
| ALL Furniture Store Limited | Extraterritorial | 2015 |
| ALL Ironed OUT Limited | Other services | 2011 |
| ALL Round Maintenance & Electrical Services Ltd | Other services | 2020 |
| Allam Carbonfree Energy Ltd | Professional & scientific | 2019 |
| Allan Biggar & Company Limited | Professional & scientific | 2012 |
| Allan Biggar Consulting Ltd | Professional & scientific | 2024 |
| Allen's Farming Limited | Agriculture & fishing | 2024 |
| Alliance Generics Limited | Extraterritorial | 2000 |
| Alliance Pharma Limited | Financial services | 2001 |
| Alliance Pharmaceuticals Limited | Manufacturing | 1996 |
| Allied Home Care Services Ltd | Administrative & support | 2024 |
| Allington Farmhouse Limited | Hospitality | 2008 |
| Allington IP Ltd | Professional & scientific | 2014 |
| Allmac Ltd | Transport & logistics | 2022 |
| Allmi Limited | Professional & scientific | 2001 |
| Allstar Construction Ltd | Construction | 2015 |
| Alpha-Promotions (Developments) Ltd | Construction | 2020 |
| Alpha-Promotions (UK) Ltd | Administrative & support | 2009 |
| Altex Properties Limited | Real estate | 2023 |
| Alto Installations Limited | Construction | 2025 |
| Alto Showrooms Limited | Wholesale & retail | 2025 |
| Altus Advisory Limited | Professional & scientific | 2016 |
| Aluna Property Management Ltd | Households | 2021 |
| Alverstoke Property Management Co Ltd | Real estate | 2012 |
| Amac Window Cleaning Limited | Administrative & support | 2009 |
| Amano Tailors Limited | Wholesale & retail | 2013 |
| Amaradigitalconsult Limited | Professional & scientific | 2026 |
| Amazing Child Limited | Wholesale & retail | 2007 |
| Ambivalent Ltd | Wholesale & retail | 2021 |
| Amelio Enterprises Limited | Construction | 2010 |
| American Retro Caravans Limited | Manufacturing | 2009 |
| AMI Homes Ltd | Real estate | 2025 |
| Amor Vincit Ltd | Information & communication | 2020 |
| Amor Vodka Ltd | Wholesale & retail | 2023 |
| Ampes Ltd | Construction | 2014 |
| Amphlett Carpentry Limited | Construction | 2003 |
| Ampj Consulting Limited | Professional & scientific | 2018 |
| Amps Electrical Services (Wilts) Ltd | Administrative & support | 2009 |
| AMY (South West) Limited | Wholesale & retail | 2007 |
| Analysis & Design Ltd | Information & communication | 2022 |
| Anarc Electrical Contractors Ltd | Construction | 2025 |
| Anbest Limited | Financial services | 2020 |
| Anchor Residential Ltd | Real estate | 2025 |
| Anchor Supporting Services Limited | Health & social care | 2026 |
| Anderson Digital Services Limited | Information & communication | 2024 |
| Andover Consultants Ltd. | Professional & scientific | 2011 |
| Andrew Jackson Holdings Limited | Other services | 2015 |
| Andrew Walker Safety Services Ltd | Construction | 2025 |
| Andrew Wilkins Holdings Ltd | Financial services | 2026 |
| Andrew Wilkins Limited | Wholesale & retail | 2002 |
| Andy Cook Cycling Limited | Arts & recreation | 2009 |
| Andy Jennings Plumbing & Heating Limited | Construction | 2007 |
| Andy Joad Roofing Limited | Construction | 2015 |
| Andy Smith Agricultural Contractor Limited | Agriculture & fishing | 2009 |
| Anglo European Pipelines Limited | Other services | 1998 |
| Anglo European Utilities Limited | Administrative & support | 2014 |
| Anglotaz Holdings Ltd | Real estate | 2024 |
| Animal Transport Services Ltd | Agriculture & fishing | 2026 |
| Anke Consulting Limited | Professional & scientific | 2022 |
| Anstead Estates LLP | | 2017 |
| Anthology Limited | Information & communication | 1997 |
| Anthony Higgins International Ltd | Wholesale & retail | 2024 |
| Anthonydodge.Tv Limited | Information & communication | 2015 |
| Antidote Projects Ltd | Professional & scientific | 2014 |
| Antidote Property Ltd | Real estate | 2021 |
| Anton Plumbing & Heating Ltd | Construction | 2018 |
| Anton Property Management Ltd | Real estate | 2023 |
| Anve Partnership Ltd | Manufacturing | 2017 |
| Aora Health Limited | Professional & scientific | 2024 |
| APD Compliance Solutions Limited | Professional & scientific | 2019 |
| APD Global Group Limited | Information & communication | 2019 |
| APD Global Research Limited | Information & communication | 2006 |
| Aperta Skin Ltd | Manufacturing | 2025 |
| Apex Boilers Limited | Construction | 2021 |
| Apex Rail Consultancy Ltd | Professional & scientific | 2020 |