| Aberfeldy Village (2) Management Limited | Households | 2014 |
| Aberfeldy Village Block Management Company Limited | Households | 2017 |
| Aberfeldy Village Estate Management Company Limited | Households | 2017 |
| Abode Management Company (Bedminster) Limited | Households | 2016 |
| Absolute Graphics (Southampton) Limited | Professional & scientific | 2003 |
| Acarlar Limited | Hospitality | 2022 |
| ACG Management Consultants Ltd | Professional & scientific | 2006 |
| Achurch & Bartlett Property Limited | Real estate | 2025 |
| Ackland Close Estate Management Company Limited | Households | 2016 |
| Ackland Close Flats Management Company Limited | Households | 2016 |
| Acorn Joinery Limited | Manufacturing | 2000 |
| Acrobat Imaging LLP | | 2007 |
| AD New Milton Ltd | Other services | 2019 |
| Added Plus Ltd | Professional & scientific | 2013 |
| ADH Composites Ltd | Manufacturing | 2020 |
| Admirals Court Management Co. Limited | Households | 1966 |
| Aerial Land Surveys Limited | Professional & scientific | 2018 |
| Aesthetic Creations Limited | Other services | 2010 |
| AG1 Homes Management Company Limited | Households | 2005 |
| Agusta Park Flats Yeovil Management Company Limited | Households | 2017 |
| Aiming High Consultancy Services Limited | Professional & scientific | 2018 |
| Ainsworth Property Developments Limited | Construction | 2011 |
| Ainsworth Property Services Limited | Real estate | 2017 |
| Airborne Surveillance (UK) Limited | Professional & scientific | 2009 |
| Airflow (Nicoll Ventilators) Limited | Manufacturing | 1972 |
| Airflow Building Products Limited | Extraterritorial | 2007 |
| AL Services (New Forest) Limited | Construction | 2003 |
| Albion Mill (Worcester) Management Company Limited | Households | 2005 |
| Albions Residents Limited | Households | 1998 |
| Alcadi Limited | Professional & scientific | 2013 |
| Aldbury Court (Barton on Sea) Management Company Limited | Real estate | 2023 |
| Alderbury Management Limited | Households | 1990 |
| Alexander Adams Mortgage Services Ltd | Financial services | 2017 |
| Alexjcb Ltd | Health & social care | 2022 |
| Alfa Fire Safety Limited | Construction | 2026 |
| Alfred's Gate (Newton Poppleford) Management Company Limited | Households | 2018 |
| Algebra Business Consultancy Ltd | Professional & scientific | 2009 |
| Alkham Road RTM Company Limited | Households | 2025 |
| ALL Accounting Limited | Professional & scientific | 2014 |
| ALL Aspect Creations (Dorset) Ltd | Wholesale & retail | 2026 |
| ALL Aspect Flooring Ltd | Wholesale & retail | 2022 |
| ALL Clear Pest Control (Southern) Limited | Agriculture & fishing | 2019 |
| Allans PMI Limited | Financial services | 2002 |
| Allen-On-Air Media Productions Limited | Administrative & support | 2009 |
| Alliance Home Improvements Ltd | Construction | 2025 |
| Alms Meadow (Etwall) Management Limited | Households | 2016 |
| Alpha (Bodmin) Management Company Limited | Households | 2007 |
| Alpha Performance Management Limited | Information & communication | 1999 |
| Altdam Farm Management Company Limited | Households | 1984 |
| Alternity Apparel Ltd | Wholesale & retail | 2014 |
| Alvandi Gardens Maintenance Limited | Real estate | 1983 |
| Alveley View Management Company Limited | Households | 2021 |
| Amalee Accounting Solutions Limited | Extraterritorial | 2010 |
| Amberlight Trading Ltd | Hospitality | 2024 |
| Amigo Tours Ltd | Administrative & support | 2015 |
| Ampress Park Management Limited | Administrative & support | 2002 |
| Ampthill Chase Management Company Limited | Households | 2016 |
| Amspac Limited | Administrative & support | 2002 |
| AMW Electrical (New Forest) Ltd | Construction | 2021 |
| AMY Russell Taylor Jewellery Limited | Manufacturing | 2021 |
| Andrew Applin Construction Limited | Construction | 2015 |
| Andrew Gates Limited | Construction | 2011 |
| Andrew Hicks & Associates Ltd | Construction | 2017 |
| Andrew Williamson Garden Design Limited | Administrative & support | 2023 |
| Anmak Surfacing Ltd | Construction | 2023 |
| Annabel Therapy Ltd | Health & social care | 2019 |
| Anstis Capital Ltd | Information & communication | 2024 |
| Anthony J Harris Solicitors Limited | Professional & scientific | 2018 |
| AP Marine Engineering Limited | Manufacturing | 2019 |
| APO New Ltd | Other services | 2024 |
| Appello Careline Limited | Other services | 1996 |
| Appello Holdings Limited | Professional & scientific | 2019 |
| Appello Limited | Professional & scientific | 2007 |
| Appello MCL Careline Limited | Other services | 2015 |
| Appello Smart Living Solutions Limited | Construction | 1979 |
| April Cottage SO41 Limited | Real estate | 2022 |
| Aquarius (Witney) Management Company Limited | Households | 2005 |
| Aquatude Management Company Limited | Households | 2007 |
| Archdale Place (New Malden) Management Company Limited | Households | 2000 |
| Arden Fields (Bulkington) Management Company Limited | Households | 2023 |
| Arden Planning Services Limited | Professional & scientific | 2020 |
| Arete Achieve CIC | Education | 2026 |
| Argyll Mews Management Company Limited | Households | 1999 |
| Ariadne (Portsmouth) Management Company Limited | Households | 2006 |
| Arimar Transport Ltd | Transport & logistics | 2021 |
| Arisdale (Phase 2) Residents Management Company Limited | Households | 2015 |
| Arlesey Grange Management Company Limited | Households | 2020 |
| Arlington Court (Barton) Freehold Company Limited | Real estate | 2004 |
| Arlington House (Teignmouth) Management Limited | Real estate | 2006 |
| Arnewood Motor Company Ltd | Extraterritorial | 2013 |
| Arquero Management Limited | Administrative & support | 2009 |
| Artaze Hair Ltd | Other services | 2015 |
| Artist Nails (BM) Limited | Other services | 2018 |
| Ascend Hair Limited | Other services | 2011 |
| ASH Management (Taunton) Limited | Real estate | 2009 |
| Ashby Grange Limited | Households | 1997 |
| Ashby Heights Management Company Limited | Households | 2008 |
| Ashdale Court Freehold Limited | Households | 2007 |
| Ashleigh Mount Management Company Limited | Households | 1981 |
| Ashley Clinton Manor Holdings Limited | Financial services | 2016 |