| Aperio Financial Solutions Limited | Professional & scientific | 2014 |
| Apero Bars Limited | Hospitality | 2007 |
| Aperture Records Ltd | Arts & recreation | 2008 |
| Apex Digital Vision Ltd | Information & communication | 2024 |
| Apex Employment Solicitors Ltd | Professional & scientific | 2018 |
| Apex Esports Lounge Ltd | Arts & recreation | 2025 |
| Apex LAB Ltd | Information & communication | 2021 |
| Apex Motorhome Services Ltd | Wholesale & retail | 2022 |
| Apex Partitions Ltd | Construction | 2025 |
| Apex Solutions Electrical Services Ltd | Construction | 2018 |
| Apex Trade Credit Consultants Limited | Administrative & support | 2003 |
| Apexway Property Limited | Real estate | 2025 |
| APG Delivery Ltd | Transport & logistics | 2016 |
| API Mechanical (UK) Limited | Construction | 2025 |
| Apiary Electrical Ltd | Construction | 2026 |
| APM Property Holdings Ltd | Real estate | 2026 |
| Apogee Corporation Limited | Information & communication | 1993 |
| Apogee Europe Limited | Information & communication | 2006 |
| Apogee Group Limited | Financial services | 2007 |
| Apogee Rentals Limited | Administrative & support | 1992 |
| Apollo Construction Services Limited | Construction | 2003 |
| Apollo Mechanical Services (South East) Limited | Professional & scientific | 2006 |
| Apollo Private Hire Limited | Transport & logistics | 2014 |
| Apollo Trade Windows Limited | Financial services | 2004 |
| Apollo Windows Ltd | Extraterritorial | 2012 |
| Apollomech Services Limited | Energy | 2022 |
| App Bang Wallop Limited | Information & communication | 2019 |
| Appamma Kitchen Ltd | Hospitality | 2025 |
| Apple Logistics Ltd | Wholesale & retail | 2007 |
| Apple Tree Gardens (Walmer) Management Company Limited | Households | 2024 |
| Applefields Ltd | Construction | 2002 |
| Appletree (Kent) Limited | Extraterritorial | 2018 |
| Appleyard Tree Care Ltd | Administrative & support | 2023 |
| Applied Accountancy Limited | Professional & scientific | 1999 |
| Applied Management Associates Limited | Professional & scientific | 2013 |
| Apply Mortgage Protection Ltd | Financial services | 2018 |
| Appnano Europe Limited | Professional & scientific | 2013 |
| Appropriate Vehicle Solutions Ltd | Administrative & support | 2019 |
| Apps Management Limited | Information & communication | 2013 |
| Apptimal Ltd | Information & communication | 2015 |
| APRIORI89 Ltd | Transport & logistics | 2022 |
| Aprodu Ltd | Health & social care | 2014 |
| APW GAS Limited | Construction | 2015 |
| APW Technical Ltd | Other services | 2017 |
| AQB Land and Property Ltd | Real estate | 2019 |
| AQL Property Ltd | Real estate | 2022 |
| Aqua Mechanical Services Ltd | Energy | 2017 |
| Aquacomp Ltd | Construction | 2022 |
| Aquarius Soft Furnishings Ltd | Administrative & support | 2017 |
| Aquatic Landscapes Limited | Construction | 2021 |
| Aquavent Systems Ltd | Administrative & support | 2007 |
| Aquaviva Properties Ltd | Real estate | 2026 |
| Aqvila Construction Ltd | Construction | 2016 |
| AR Inspired Ltd | Wholesale & retail | 2005 |
| ARA Medical Limited | Health & social care | 2019 |
| ARA Structural Design Limited | Professional & scientific | 2010 |
| Aragon Tower RTM Company Limited | Households | 2021 |
| Aral Liryc Group Limited | Information & communication | 2015 |
| Arazioni Ltd | Information & communication | 2022 |
| ARB Decorators Ltd | Construction | 2021 |
| ARC Cinema Solutions Ltd | Administrative & support | 2013 |
| ARC Electrical & Property Services Ltd | Construction | 2022 |
| ARC Electrical Contractors & Building Services Ltd | Construction | 2021 |
| ARC Facilities South East Ltd | Water & waste | 2020 |
| ARC Holdings Kent Ltd | Other services | 2024 |
| ARCH2 Limited | Financial services | 2023 |
| ARCH24 Healthcare Limited | Health & social care | 2019 |
| Archer Capital Limited | Professional & scientific | 2013 |
| Archers Park (Management Company) Limited | Professional & scientific | 2006 |
| Archetypes Consulting Ltd | Administrative & support | 2022 |
| Archi Internal Audit Consulting Limited | Professional & scientific | 2013 |
| Architechnology Build Ltd | Construction | 2022 |
| Architects, Surveyors and Planners (Southern) Ltd | Professional & scientific | 1990 |
| Architectural Lead & Metalwork (London) Ltd | Manufacturing | 2024 |
| Architectural Properties (Developments) 1 Limited | Households | 2015 |
| Architectural Properties (Developments) Limited | Construction | 2009 |
| Architectural Wraps UK Ltd | Other services | 2019 |
| Archway Gardens Ltd | Administrative & support | 2025 |
| Arcouk Ltd | Construction | 2026 |
| ARCS(PH)2 Limited | Financial services | 2023 |
| Arctic Gargoyle Limited | Construction | 2015 |
| Ardee Hose Limited | Wholesale & retail | 2005 |
| Arden Bridge Limited | Professional & scientific | 2026 |
| Ardojud Corporate Ltd | Wholesale & retail | 2023 |
| Arena Media Limited | Professional & scientific | 2005 |
| Areos Holdings Limited | Real estate | 2023 |
| Ares Network Services Ltd | Construction | 2020 |
| Aretalk Education Tech Limited | Information & communication | 2015 |
| Argon Capital Management Limited | Real estate | 2025 |
| Ariana Tandoori Ltd | Hospitality | 2025 |
| Ariane Poole Cosmetics Ltd | Wholesale & retail | 2014 |
| Arianna Transport Ltd | Transport & logistics | 2024 |
| Arikay Ltd | Wholesale & retail | 2025 |
| Arimo Consulting Ltd | Professional & scientific | 2007 |
| ARK Contractors Ltd | Construction | 2025 |
| ARK Properties Kent Limited | Construction | 2021 |
| Arkas Limited | Manufacturing | 1988 |
| Arkasfd Limited | Construction | 2023 |
| Arkdent Limited | Health & social care | 2024 |
| Arking Properties Limited | Real estate | 2024 |