| Abistouch Salon & Cosmetic Products Limited | Wholesale & retail | 2023 |
| ABJ Spedition Ltd | Transport & logistics | 2024 |
| Abjn Limited | Wholesale & retail | 2011 |
| Abledale Homecare Ltd | Health & social care | 2022 |
| Ablesim Ltd | Information & communication | 2015 |
| ABM Capital Ltd | Information & communication | 2008 |
| Abmtech Consulting Limited | Information & communication | 2022 |
| Abodebee Limited | Households | 2018 |
| Aboliv Ltd | Real estate | 2025 |
| Abooteks Limited | Health & social care | 2022 |
| Abortion Support Network | Other services | 2009 |
| Above & Beyond Bathroom Limited | Construction | 2021 |
| Above and Beyond Care (WM) Limited | Health & social care | 2024 |
| Above and Beyond Care Devon Limited | Health & social care | 2020 |
| Above and Beyond Care Properties Limited | Financial services | 2021 |
| Above and Beyond Renovations Limited | Other services | 2019 |
| Above Bar Properties Limited | Real estate | 2016 |
| Above Dynamics Limited | Financial services | 2017 |
| ABP Restaurants Limited | Hospitality | 2008 |
| ABP UK Properties Ltd | Real estate | 2024 |
| ABR RBA Limited | Administrative & support | 2026 |
| Abrafi Investments Limited | Real estate | 2021 |
| Abraham and Ahana Textiles Ltd | Wholesale & retail | 2024 |
| Abrakebabra Limited | Professional & scientific | 2011 |
| Abrc Limited | Wholesale & retail | 2005 |
| Abroad ARK Media Limited | Information & communication | 2024 |
| Abroad for Pleasure Ltd | Administrative & support | 2023 |
| Abrol Limited | Real estate | 1999 |
| ABS Blackstone Ltd | Health & social care | 2022 |
| Absb Express Ltd | Other services | 2018 |
| Abshire Properties Limited | Real estate | 2021 |
| Abshire Solutions Limited | Professional & scientific | 2018 |
| Absolute Agile Ltd | Information & communication | 2017 |
| ABT Store Ltd | Wholesale & retail | 2026 |
| ABU Bham Ltd | Wholesale & retail | 2025 |
| Abubakar Mullan Parcels Ltd | Transport & logistics | 2026 |
| Abubakar Ventures Ltd | Wholesale & retail | 2026 |
| Abuls Limited | Hospitality | 2015 |
| Abumisk Delivery Services Ltd | Transport & logistics | 2020 |
| Abxyz Ltd | Other services | 2023 |
| Abymed Limited | Health & social care | 2024 |
| Abyss Ltd | Information & communication | 2016 |
| ABZ Motors Limited | Wholesale & retail | 2016 |
| AC Commercial Property Ltd | Real estate | 2024 |
| AC Elite Fitness Ltd | Education | 2025 |
| AC Property Investments (Midlands) Ltd | Real estate | 2018 |
| AC Quarterlight Ltd | Wholesale & retail | 2014 |
| AC Salvador Services Limited | Information & communication | 2023 |
| AC8 Cars Ltd | Wholesale & retail | 2024 |
| Acacia Healthcare Services Ltd | Health & social care | 2024 |
| Academy of Glasgow for Culture & Sciences Limited | Education | 2019 |
| Academy of Oxford International Ltd | Professional & scientific | 2017 |
| Acadexus Educational Services Ltd | Administrative & support | 2026 |
| Acaia Health AI Ltd | Information & communication | 2026 |
| Acaiberry Ltd | Wholesale & retail | 2026 |
| Acajou Services Ltd | Health & social care | 2018 |
| Acan Ltd | Professional & scientific | 2011 |
| Acao Property Limited | Real estate | 2025 |
| ACB Robotics Limited | Professional & scientific | 2011 |
| Accentiv Limited | Administrative & support | 2008 |
| ACCESS2SQL Limited | Information & communication | 2011 |
| Accessible IT Limited | Information & communication | 1996 |
| Accessory House Global Limited | Wholesale & retail | 2015 |
| Accessries Mart Ltd | Wholesale & retail | 2025 |
| Accident Line Coventry Ltd | Wholesale & retail | 2025 |
| Acclaim Property Group Ltd | Real estate | 2022 |
| Acclaimed Mortgage Consultancy Ltd | Financial services | 2020 |
| Accomconsult Ltd | Hospitality | 2024 |
| Accountae Ltd | Information & communication | 2018 |
| Accountracy Ltd | Professional & scientific | 2025 |
| Accounts Solutions Limited | Professional & scientific | 2006 |
| Accra Retail Ltd | Wholesale & retail | 2023 |
| Accredo Support and Development Ltd. | Health & social care | 2003 |
| Accretech-Sbs UK Ltd. | Manufacturing | 1996 |
| Accsys Projects Limited | Construction | 2003 |
| Accsys Trustees Limited | Professional & scientific | 2023 |
| Acctec Progressive Solutions Limited | Information & communication | 2016 |
| Accumen Business Consultancy Limited | Professional & scientific | 2002 |
| Accurate Accounts & Consultancy Limited | Administrative & support | 2003 |
| Accuro Housing Ltd | Hospitality | 2021 |
| Accutemp Limited | Manufacturing | 2013 |
| Acds Driving Limited | Transport & logistics | 2023 |
| Ace 2 Properties Ltd | Real estate | 2025 |
| Ace Account Solutions Ltd. | Real estate | 2014 |
| Ace Architectural Products Limited | Manufacturing | 2009 |
| Ace Consulting and Trading Ltd | Construction | 2020 |
| Ace Flights Ltd | Administrative & support | 2022 |
| Ace Golf Management Limited | Education | 2009 |
| Ace Infinity Solutions Ltd | Information & communication | 2021 |
| Ace Invesments Ltd | Households | 2026 |
| Ace IT Solutions Ltd | Information & communication | 2007 |
| Ace MB Ltd | Information & communication | 2026 |
| Ace Vapes Ltd | Wholesale & retail | 2016 |
| Ace Workplace Learning Limited | Education | 2016 |
| Acendia Limited | Real estate | 2017 |
| Aces Cleaning Ltd | Other services | 2017 |
| Aces Vibe Ltd | Arts & recreation | 2014 |
| Acetastic Ltd | Manufacturing | 2014 |
| Acetel (UK) Limited | Manufacturing | 2018 |
| Acetherix Healthcare Ltd | Manufacturing | 2021 |