| Applied Knowledge Consulting Limited | Professional & scientific | 2025 |
| Applied Market Information Limited | Professional & scientific | 1987 |
| Applied Product Design Ltd | Extraterritorial | 2011 |
| Apply Design Ltd | Administrative & support | 2019 |
| Apply Structure Ltd | Administrative & support | 2017 |
| Appointly Limited | Information & communication | 2025 |
| Apposite Technology Partners Ltd | Information & communication | 2012 |
| Appraisers UK Ltd | Professional & scientific | 2009 |
| Apprenticeshipsupport Ltd | Education | 2016 |
| Appropriate RPE Services Limited | Administrative & support | 2018 |
| Approved Contractors (SW) Ltd | Construction | 2021 |
| Approved Group (SW) Limited | Construction | 2019 |
| Approved Plastering Specialist Ltd | Construction | 2011 |
| Approved Rendering Specialists Ltd | Construction | 2025 |
| Approved Roofing & Landscaping Ltd | Construction | 2026 |
| Approved Roofing Southwest Ltd | Construction | 2022 |
| Apps Cloud Consulting Ltd | Information & communication | 2019 |
| Appsly Limited | Information & communication | 2019 |
| APR Retail Group Ltd | Wholesale & retail | 2024 |
| Apricity Healthcare Ltd | Health & social care | 2025 |
| Apricot Property SW Ltd | Real estate | 2022 |
| April Aesthetics Ltd | Health & social care | 2022 |
| April Boulton Limited | Professional & scientific | 2022 |
| April House Support Services Limited | Administrative & support | 2009 |
| April Lodge Developments Ltd | Real estate | 2021 |
| Aprnexus Ltd | Wholesale & retail | 2025 |
| Apro Contract Services Limited | Construction | 2015 |
| Apropos Consulting Ltd | Professional & scientific | 2012 |
| Apropos Energy Limited | Energy | 1999 |
| Aprotax Ltd | Professional & scientific | 2019 |
| APS Bristol Ltd | Construction | 2025 |
| APS GAS Bristol Limited | Construction | 2025 |
| APS Mobility AID Mission Ltd | Other services | 2025 |
| Apsley Carpentry Ltd | Manufacturing | 2025 |
| Apsley Consulting Limited | Professional & scientific | 2017 |
| Apsley Holdings Limited | Financial services | 2025 |
| Apst Ltd | Information & communication | 2010 |
| APT Action on Poverty | Professional & scientific | 1984 |
| APT Global Venture Ltd | Financial services | 2020 |
| APT Home Renovations Ltd | Real estate | 2023 |
| APT Perspective Ltd | Information & communication | 2015 |
| APT Safety Solutions Limited | Construction | 2017 |
| Aptamo Limited | Information & communication | 2010 |
| Aptcore Limited | Information & communication | 2010 |
| Apto Solutions Limited | Information & communication | 2004 |
| Apuntar Alto Ltd | Hospitality | 2018 |
| Apurimac Consulting Limited | Professional & scientific | 2019 |
| APW Hire Ltd | Information & communication | 2018 |
| APX Training and Development Company Ltd | Professional & scientific | 2022 |
| AQ Motor Group Limited | Wholesale & retail | 2024 |
| Aqss Business Services Ltd | Other services | 2013 |
| Aqss Retail Limited | Wholesale & retail | 2014 |
| Aqua Bathrooms Bristol Limited | Construction | 2018 |
| Aqua Furnishings Ltd | Wholesale & retail | 2021 |
| Aqua Heat Assure Ltd | Construction | 2025 |
| Aqua Kleen South West Limited | Administrative & support | 2015 |
| Aqua Savage Designs Ltd | Arts & recreation | 2017 |
| Aqua Systems Design Limited | Professional & scientific | 2014 |
| Aqua Washroom Solutions Ltd | Water & waste | 2007 |
| Aqua Window and Property Cleaning Services Limited | Administrative & support | 2021 |
| Aqua Window Cleaning Limited | Administrative & support | 2017 |
| Aqua-Solutions Property Services Ltd | Construction | 2013 |
| Aquaclean Bristol Ltd | Administrative & support | 2023 |
| Aquacyan Consultants Ltd. | Professional & scientific | 2014 |
| Aquafloor Heating Ltd | Construction | 2026 |
| Aquaflora Landscapes Limited | Administrative & support | 2018 |
| Aquagas Bristol Limited | Construction | 2018 |
| Aquaid (Western) Ltd | Wholesale & retail | 2002 |
| Aquajas Property Investments Holdings Ltd | Real estate | 2019 |
| Aqualogic Consulting Limited | Professional & scientific | 2014 |
| Aquamarine Consultancy Limited | Professional & scientific | 2017 |
| Aquamaster (Bristol) Limited | Administrative & support | 2007 |
| Aquana Limited | Real estate | 2021 |
| Aquarela Developments Limited | Other services | 2007 |
| Aquaries Performance Coaching Ltd | Education | 2024 |
| Aquarium Enterprises Ltd | Administrative & support | 2012 |
| Aquarius Cleaning & Floor Maintenance Limited | Administrative & support | 2012 |
| Aquarius Communications Ltd. | | 1985 |
| Aquatak Limited | Agriculture & fishing | 1990 |
| Aquatak Waterscapes Ltd | Administrative & support | 2024 |
| Aquataur Ltd | Professional & scientific | 2007 |
| Aquatec Servicing and Maintenance Limited | Households | 2011 |
| Aquatonics (UK) Limited | Construction | 2007 |
| Aquatronic (Holdings) Limited | Real estate | 2018 |
| Aquawaste Solutions Limited | Extraterritorial | 2010 |
| Aquifolio Limited | Manufacturing | 2002 |
| Aquila Design Ltd | Professional & scientific | 2012 |
| Aquila Group Limited | Professional & scientific | 2020 |
| Aquitech LLP | | 2023 |
| AQX Ltd | Construction | 2026 |
| AR & KN Limited | Health & social care | 2014 |
| AR Agile Consultancy Ltd | Information & communication | 2020 |
| AR Brand Ltd | Wholesale & retail | 2021 |
| AR Car & Van Body Repairs Limited | Wholesale & retail | 2025 |
| AR Chippenham Limited | Wholesale & retail | 2020 |
| AR Flooring Bristol Ltd | Wholesale & retail | 2021 |
| AR Organics UK Ltd | Other services | 2024 |
| AR Plumbing & Bathrooms Ltd | Other services | 2018 |
| AR Renovations Ltd | Construction | 2026 |
| AR Technology Consultants Ltd | Information & communication | 2021 |