| AK Group Consultants Limited | Professional & scientific | 2024 |
| AK Pro Limited | Administrative & support | 2012 |
| Akon Security Services Limited | Administrative & support | 2012 |
| Alandy Investment Properties Limited | Real estate | 2016 |
| Alandy Residential Investment Properties Limited | Real estate | 2018 |
| ALB Construction Services Ltd | Construction | 2026 |
| Albert Street Management Limited | Extraterritorial | 1999 |
| Albion Construction Limited | Construction | 2019 |
| Alejamte Ltd | Manufacturing | 2023 |
| Alexander Electrical Ltd | Construction | 2003 |
| Alexandra Road Association Limited | Professional & scientific | 2015 |
| ALL Business Affairs Limited | Administrative & support | 1982 |
| ALL Clear Windows (Kent) Limited | Construction | 2015 |
| ALL Tyres and Wheels (Kent) Ltd | Wholesale & retail | 2023 |
| Allstyle Building Limited | Construction | 2025 |
| Alman Design Ltd | Manufacturing | 2020 |
| Almasea Ltd | Wholesale & retail | 2021 |
| Alpha Innovation Build Ltd | Construction | 2024 |
| Altobo Ltd | Information & communication | 2008 |
| Altruist Investments Limited | Professional & scientific | 2016 |
| Altruistic (North Kent) Ltd | Health & social care | 2015 |
| Amazonian Wellbeing Ltd | Education | 2025 |
| Ambition Motorsport Limited | Administrative & support | 2018 |
| Amco Rentals Ltd | Real estate | 2020 |
| AMDAR2 Limited | Financial services | 2024 |
| Amedea Ltd | Hospitality | 2021 |
| Ameeco Holiday Apartments Ltd | Hospitality | 2015 |
| Amelix Education Resources Limited | Education | 2013 |
| Amelix Limited | Information & communication | 2008 |
| Amolo Developments Ltd | Administrative & support | 2023 |
| Amphenol Limited | Manufacturing | 1963 |
| Amphenol Trackwise Designs Limited | Manufacturing | 2023 |
| AMT Plumbing and Electrical Services Ltd | Construction | 2024 |
| Anaik Property Ltd | Real estate | 2026 |
| Analytical Insight Limited | Information & communication | 2025 |
| Anassgh Ltd | Professional & scientific | 2024 |
| Ancestral Footsteps Limited | Information & communication | 1998 |
| Andem Ltd | Real estate | 2020 |
| Anderson Rigden & Perkins Limited | | 1945 |
| Andrew Cozens Entertainment Limited | Arts & recreation | 2022 |
| Andrew M Johnson Ltd | Professional & scientific | 2014 |
| Andy Neal Ltd | Financial services | 2024 |
| ANG Excellence Limited | Professional & scientific | 2020 |
| Anglian Taxi Services Limited | Transport & logistics | 2001 |
| Annie Fontaine Life Coaching Ltd | Health & social care | 2022 |
| Antony James Limited | Information & communication | 2012 |
| Anystate International Limited | Transport & logistics | 2006 |
| Anystory Ltd | Professional & scientific | 2023 |
| Apex Security Services Ltd | Administrative & support | 2025 |
| APG Building Solutions Limited | Construction | 2019 |
| APH Consultancy Services Ltd | Professional & scientific | 2020 |
| Aquajaks Ltd | Construction | 2020 |
| Aqvr Ltd | Manufacturing | 2025 |
| Ariana Consulting Ltd | Information & communication | 2024 |
| Armature Electrical Limited | | 2010 |
| Arrant Enterprises Limited | Professional & scientific | 2025 |
| Art Palette Limited | Arts & recreation | 2024 |
| Art Unscrewed Limited | Arts & recreation | 2018 |
| Artisan Collaboration Whitstable Ltd | Real estate | 2016 |
| Artistic Movement Ltd | Information & communication | 2008 |
| Artwise Community Partnership C.I.C. | Education | 2013 |
| Arundel & Coult Contracts Ltd | Construction | 2021 |
| ASA Clinical Limited | Professional & scientific | 2012 |
| Asafeas Ltd | Professional & scientific | 2021 |
| ASG Recovery and Transport Ltd | Transport & logistics | 2016 |
| ASH Construction Group Ltd | Administrative & support | 2012 |
| Asherrail Limited | Construction | 2022 |
| Ashford Hearing Ltd | Wholesale & retail | 2025 |
| Ashford Plant Ltd | Wholesale & retail | 2023 |
| Ashurst Wood Abbey Management Company Limited | Households | 1985 |
| ASP Education Recruitment Ltd | Administrative & support | 2022 |
| Asquith Associates Limited | Professional & scientific | 2021 |
| Assiduous Heating Ltd | Construction | 2023 |
| Assign (UK) Limited | Professional & scientific | 2003 |
| Asv&Partners Tech Ltd | Information & communication | 2025 |
| AT Accounts Limited | Professional & scientific | 2013 |
| AT Specialist RGN Health-Services Limited | Health & social care | 2017 |
| AT Swim Ltd | Information & communication | 2019 |
| Athenia Aesthetics Limited | Other services | 2024 |
| Atlantic Pathways Group Ltd | Administrative & support | 2026 |
| Atlas House Limited | Real estate | 2007 |
| Atman Sound Limited | Information & communication | 2026 |
| Attwoolls Ltd | Arts & recreation | 2024 |
| Auraohm Ltd | Real estate | 2024 |
| Auriga Developments Limited | Extraterritorial | 2005 |
| Aurora Therapy Centre Limited | Health & social care | 2025 |
| Austin & Co. (Whitstable) Limited | Professional & scientific | 2017 |
| Auto PRX Limited | Information & communication | 2021 |
| Autoforum Ltd | Wholesale & retail | 2022 |
| Avant Garde Equestrian Limited | Wholesale & retail | 2021 |
| Avocet Insurance Consultants Ltd | Financial services | 2020 |
| Avocet Risk Management Limited | Financial services | 2011 |
| AWE Services Ltd | Energy | 2018 |
| AX7 Limited | Professional & scientific | 2012 |
| Aydinbey Ltd | Hospitality | 2022 |
| Azimuth Ventures Ltd | Construction | 2019 |
| Azure Property Consultants Ltd | Real estate | 2003 |
| B G Security Limited | Construction | 2022 |
| B&C Roofing (Kent) Ltd | Construction | 2021 |
| B. Wahl & Co. Contractors (Kent) Limited | Construction | 1979 |