| ABC Cleaning Limited | Administrative & support | 2009 |
| ABC Staycations Ltd | Hospitality | 2023 |
| ABE Social Limited | Professional & scientific | 2021 |
| Abe's School of Motoring Ltd | Education | 2020 |
| Abel Driveways Ltd | Construction | 2020 |
| Abelitefitness Ltd | Arts & recreation | 2025 |
| Abeya Medical Limited | Real estate | 2011 |
| Abhipriya Housing Limited | Real estate | 2025 |
| Abidaramz Properties Ltd | Real estate | 2021 |
| Abieva Ventures Limited | Households | 2022 |
| Ability Support Care Ltd. | Health & social care | 2013 |
| Abingdon Court Farm Management Limited | Households | 2001 |
| Abingdon Management Company Limited(The) | Professional & scientific | 1980 |
| Abino & Co Limited | Real estate | 2022 |
| Abiphe Limited | Administrative & support | 2022 |
| Able Waste Management Limited | Extraterritorial | 2001 |
| Abode Time Limited | Real estate | 2021 |
| Above and Beyond Training Academy Ltd | Other services | 2025 |
| ABP Dudley Limited | Real estate | 2022 |
| ABP Investments Limited | Financial services | 2018 |
| ABR Safety Limited | Professional & scientific | 2016 |
| Abraham & Co Ltd | Real estate | 2021 |
| Abridaj Ltd | Wholesale & retail | 2020 |
| Absolute Construction Group Ltd | Construction | 2025 |
| Absolute Corporate Events Limited | Administrative & support | 2013 |
| Absolute Motor Care Limited | Wholesale & retail | 2009 |
| Absolute Mots Limited | Wholesale & retail | 2026 |
| Absolute Rubbish (SW) Ltd | Administrative & support | 2016 |
| Absolutely Banknotes Limited | Wholesale & retail | 2021 |
| Absolutely Fit Ltd | Arts & recreation | 2022 |
| Absorbia Pro UK Limited | Other services | 2025 |
| Abstract Corporation Limited | Arts & recreation | 2013 |
| Abstract I.T. Management Limited | Manufacturing | 2013 |
| Abstract IT Management Services Limited | Information & communication | 2019 |
| Abstract Professional Coaching Practice Ltd | Other services | 2017 |
| AC / BC Design & Build Services Ltd | Professional & scientific | 2021 |
| ACA Acoustics Limited | Professional & scientific | 2012 |
| Acacia Enterprises UK Ltd | Administrative & support | 2011 |
| Academy Damp Proofing Ltd | Construction | 2012 |
| Acadia Windows & Doors Ltd | Construction | 2013 |
| ACB Building and Electrical Services Ltd. | Construction | 2012 |
| Accentua Group Limited | Financial services | 2021 |
| Accentua Language Company Limited | Information & communication | 2013 |
| Access Displays Limited | Administrative & support | 1990 |
| Access Franchise Management Limited | Financial services | 1957 |
| Accomplish HR Limited | Professional & scientific | 2010 |
| Accountancy Contracting Solutions Limited | Administrative & support | 2019 |
| Accounting & Licence Solutions Limited | Information & communication | 2007 |
| Accounting for Hospitality Limited | Professional & scientific | 2005 |
| Accounting Services Ltd. | Real estate | 1985 |
| Accounts on US Limited | Professional & scientific | 2014 |
| Accred-Assure Limited | Education | 2025 |
| Accuratus CIS Limited | Professional & scientific | 2025 |
| Accuratus Green Ltd. | Professional & scientific | 2015 |
| Accutrak Transport Services Limited | Transport & logistics | 2013 |
| ACD Logistics Ltd | Transport & logistics | 2024 |
| ACD Transport Ltd | Transport & logistics | 2016 |
| Ace Fuelcards Ltd | Financial services | 2006 |
| Ace Scaffolding (Swindon) Ltd | Construction | 2013 |
| Ace Skips Ltd | Water & waste | 2014 |
| Ace Towbars Limited | Wholesale & retail | 2017 |
| Aceofwands Ltd | Professional & scientific | 2025 |
| Acer Facility Management Ltd | Construction | 2019 |
| Acerola UK Limited | Construction | 2017 |
| Acetech Autos Ltd | Wholesale & retail | 2023 |
| Achaleswar Ltd | Real estate | 2025 |
| Achaywala Ltd | Hospitality | 2024 |
| Acheron Ltd | Wholesale & retail | 2025 |
| Acheter Limited | Information & communication | 1998 |
| Achieve in Science Ltd | Education | 2025 |
| Achieve Wealth Management (Wiltshire) Limited | Financial services | 2014 |
| Achievers International Ltd | Information & communication | 2018 |
| Acif Limited | Administrative & support | 2020 |
| Acmtech Limited | Information & communication | 2014 |
| Acorn Electrical Solutions Limited | Construction | 2002 |
| Acorn Facilities Management Ltd | Administrative & support | 2007 |
| Acottscarwash Ltd | Other services | 2024 |
| Acre Technical Developments Limited | Professional & scientific | 2003 |
| Acres Retail Ltd | Manufacturing | 2020 |
| Acrion Limited | Professional & scientific | 2017 |
| Across Homes Ltd | Real estate | 2026 |
| Across Tech Ltd | Information & communication | 2023 |
| Acrux Support Services Limited | Health & social care | 2023 |
| Acsi-Europe Ltd | Professional & scientific | 1999 |
| ACT | | 1990 |
| Acta Services Ltd | Professional & scientific | 2008 |
| Action Disability Swindon | Health & social care | 2010 |
| Action Logistics Ltd | Transport & logistics | 2020 |
| Action Plant Hire Ltd | Administrative & support | 2018 |
| Activ Educate Ltd | Information & communication | 2007 |
| Acucare&Herbal Ltd | Health & social care | 2020 |
| Acura Project Management Ltd | Construction | 2019 |
| Acurutek Ltd | Professional & scientific | 2022 |
| AD Audio Ltd | Administrative & support | 2025 |
| AD Companionship Limited | Health & social care | 2025 |
| AD Haircut Swindon Ltd | Other services | 2018 |
| AD Used Parts Sale Ltd | Wholesale & retail | 2024 |
| Ad-Craftmarketing Ltd | Wholesale & retail | 2025 |
| Adam Brooks Orthopaedics Limited | Health & social care | 2021 |
| Adam Diduch Limited | Transport & logistics | 2013 |