| Arlington Building Services Ltd | Construction | 2017 |
| ARM Services Limited | Health & social care | 2017 |
| Armageddon Baits Limited | Wholesale & retail | 2024 |
| Armour Motor Products (Bournemouth) Limited | Manufacturing | 1973 |
| Armour Motors Ltd | Administrative & support | 2016 |
| Armstrong Properties Limited | Real estate | 2024 |
| Armwrap Ltd | Wholesale & retail | 2024 |
| Arna Care Home Ltd | Health & social care | 2023 |
| Arnewood Court (Bournemouth) Management Company Limited | Households | 1997 |
| Arnewood Estates (Management) Limited | Professional & scientific | 1943 |
| Arnewood Estates Limited | Hospitality | 1954 |
| Arnewood Imaging Ltd | Arts & recreation | 2011 |
| Arnewood Motor Repairs Limited | Wholesale & retail | 2003 |
| Arnewood Property Investments Limited | Professional & scientific | 1942 |
| Arngold Limited | Real estate | 1989 |
| Arnold Brothers Ltd | Construction | 2023 |
| Arnold Financial Limited | Financial services | 2015 |
| Aromamania Ltd | Wholesale & retail | 2013 |
| Arqhaus Ltd | Professional & scientific | 2026 |
| Arranmac Professional Painting & Decorating Limited | Construction | 2019 |
| Arrios Utilities Ltd | Wholesale & retail | 2019 |
| Arrival Consulting Limited | Administrative & support | 2023 |
| Arrowedge Limited | Wholesale & retail | 1982 |
| Arrowedge Properties Ltd | Real estate | 2012 |
| ARS Car Direct Ltd | Wholesale & retail | 2026 |
| ARS City CAB Limited | Transport & logistics | 2026 |
| Art & Snacks Limited | Hospitality | 2023 |
| Art Club Barbers Limited | Other services | 2025 |
| Art Collective Limited | Other services | 2024 |
| Art Glass Services Ltd | Manufacturing | 2023 |
| Art Global Trading Ltd | Wholesale & retail | 2026 |
| Art Sushi Ltd | Hospitality | 2020 |
| Artemis Fortitude Solutions Limited | Financial services | 2016 |
| Artemis Surveyors Limited | Professional & scientific | 2020 |
| Artemus Yachts Limited | Professional & scientific | 2025 |
| Artifact Lighting Limited | Wholesale & retail | 2011 |
| Artimus INK Ltd | Wholesale & retail | 2023 |
| Artins Properties Limited | Construction | 2026 |
| Artisanea Limited | Financial services | 2013 |
| Artists in Frame Ltd | Professional & scientific | 2025 |
| Artius Global Ltd | Administrative & support | 2023 |
| Artizaen Limited | Construction | 2003 |
| Artp Carpentry and Building Services Ltd | Construction | 2022 |
| Artrix Studios Ltd | Manufacturing | 2025 |
| Arts Communications Ltd | Education | 2023 |
| Aruba Limited | Hospitality | 2006 |
| Arusuvaifactory Ltd | Hospitality | 2022 |
| Arve Global Limited | Wholesale & retail | 2023 |
| Arvento Limited | Financial services | 2024 |
| ARW Training & Consultancy Ltd | Professional & scientific | 2024 |
| Arziaa Group Ltd | Wholesale & retail | 2026 |
| AS Barbering Ltd | Other services | 2024 |
| AS Mechanical and Electrical Ltd | Construction | 2017 |
| Asap Steel Limited | Wholesale & retail | 2010 |
| ASC Security Ltd | Administrative & support | 2025 |
| Ascend Marketing Consultancy Ltd | Professional & scientific | 2024 |
| Ascendia Ltd | Information & communication | 2016 |
| Ascens:On Limited | Other services | 2020 |
| Ascension Marketing Group Ltd | Information & communication | 2015 |
| Ascesis Group Limited | Information & communication | 2017 |
| Ascham Court Management Company Limited | Households | 2004 |
| ASH Developments (UK) Limited | Construction | 1999 |
| ASH Digital Technology Limited | Information & communication | 2016 |
| Ashap Limited | Other services | 2013 |
| Ashbank North & Co Limited | Administrative & support | 2009 |
| Ashcroft Property Group Ltd | Real estate | 2020 |
| Ashcroft Solutions Ltd | Information & communication | 2018 |
| Ashdale House Management Limited | Households | 2007 |
| Ashdown Administration (Bournemouth) Ltd | Households | 1996 |
| Ashdrew Homes Ltd | Extraterritorial | 2019 |
| Ashdrew Limited | Construction | 2011 |
| Ashfield Properties Limited | Real estate | 1955 |
| Ashford & Thompson Ltd | Construction | 2025 |
| Ashlet Gardens Number One Management Company Limited | Households | 1986 |
| Ashlet Gardens Number Two Management Company Limited | Households | 1986 |
| Ashley Court (Bournemouth) Management Limited | Extraterritorial | 2000 |
| Ashley Cross Store Ltd | Wholesale & retail | 2025 |
| Ashley Retail Ltd | Wholesale & retail | 2025 |
| Ashley Trading Ltd | Wholesale & retail | 2020 |
| Ashmede Freehold Limited | Households | 1997 |
| Ashmore House (Bournemouth) Maintenance Company Limited | Households | 1973 |
| Ashmore House Freehold Limited | Households | 2005 |
| Ashokan Solutions Ltd | Information & communication | 2024 |
| Ashram Health Consulting Limited | Health & social care | 2021 |
| Asid Electro-Optics Ltd | Professional & scientific | 2024 |
| Asif a Services Ltd | Extraterritorial | 2017 |
| Asik Consultancy Ltd | Other services | 2020 |
| Asjs Roofing Ltd | Construction | 2023 |
| ASK Apps Limited | Information & communication | 2026 |
| Askar Group Limited | Construction | 2025 |
| Askern Court Residents Association Limited | Households | 1987 |
| Askesis Limited | Professional & scientific | 2003 |
| Asme Holdings Limited | Financial services | 2020 |
| ASN Branksome Ltd | Real estate | 2026 |
| ASN Capital Colehill Ltd | Construction | 2017 |
| ASN Capital Construction Ltd | Construction | 2003 |
| ASN Capital Group Ltd | Professional & scientific | 2010 |
| ASN Capital Investments Ltd | Construction | 2003 |
| ASN Capital Lettings Ltd | Real estate | 2007 |
| ASN Capital Ltd | Construction | 1998 |