| A.C. Beck Holdings Limited | Professional & scientific | 2014 |
| A.P.W. Builders Ltd | Households | 2024 |
| A.R.M Optical Limited | Health & social care | 2023 |
| A1 Building Supplies & Maintenance Limited | Extraterritorial | 2013 |
| A1 Cars (Reading) Ltd | Transport & logistics | 2011 |
| A1 Design Engineering Ltd | Professional & scientific | 2022 |
| A1 Financial Services Ltd | Financial services | 2026 |
| A1 Group Transport Limited | Transport & logistics | 2021 |
| A1 LOO Hire Limited | Administrative & support | 2005 |
| A1 LOO Hire-Wokingham Limited | Professional & scientific | 2004 |
| A1 Premium Constructions Ltd | Construction | 2024 |
| A1 Vipee's Limited | Extraterritorial | 2015 |
| A1 Wokingham Car Spares Limited | Financial services | 2026 |
| A1 Wokingham WET Waste Limited | Water & waste | 2003 |
| A2S Properties Limited | Real estate | 2024 |
| A2V Consulting Ltd | Information & communication | 2025 |
| A2Z Global Trading Ltd | Wholesale & retail | 2025 |
| A3 Cleaning Services Ltd | Administrative & support | 2025 |
| A3A Consult Limited | Construction | 2020 |
| A7 Enterprises Limited | Information & communication | 2003 |
| A7C Limited | Professional & scientific | 2026 |
| A7CONSULT Limited | Professional & scientific | 2025 |
| AAB Solutions Ltd | Information & communication | 2004 |
| Aaradhvi Ltd | Real estate | 2026 |
| Aarib Wireless Limited | Information & communication | 2025 |
| Aarkeya Properties Limited | Real estate | 2026 |
| AAT Services UK Ltd | Professional & scientific | 2023 |
| Aavaas Homes Ltd | Real estate | 2018 |
| Aavik Consultants Limited | Information & communication | 2016 |
| AB Electrics (Berkshire) Ltd | Construction | 2025 |
| Ab(Uk) IT Consulting Ltd | Information & communication | 2021 |
| Abab Ltd | Professional & scientific | 2026 |
| Abacus Consultancy Team Limited | Professional & scientific | 2015 |
| Abardo Ltd | Information & communication | 2020 |
| Abberly Holdings Limited | Real estate | 2019 |
| Abberly Property Limited | Administrative & support | 2009 |
| Abbey Well Homes Ltd | Construction | 2005 |
| Abbotsmead Caversham Freehold Limited | Households | 2001 |
| ABD Construction Services Ltd | Construction | 2022 |
| Abigail Talent Solutions Ltd | Administrative & support | 2025 |
| Abiomed, Ltd. | Wholesale & retail | 2007 |
| ABL Property Services Limited | Real estate | 2022 |
| Abndon Ltd | Professional & scientific | 2023 |
| About Face Limited | Professional & scientific | 2017 |
| Abrg Limited | Financial services | 2024 |
| Abrs Building Services Limited | Construction | 2025 |
| Absolute Computers Limited | Wholesale & retail | 1977 |
| Absolute IT Services Limited | Information & communication | 2005 |
| Absolute Reflections Ltd | Manufacturing | 2010 |
| Abstraction Consultancy Limited | Information & communication | 2017 |
| AC Alto B Limited | Financial services | 2025 |
| AC Alto Limited | Financial services | 2024 |
| AC Chapter One (Siege) Limited | Information & communication | 2025 |
| AC Chapter One Limited | Information & communication | 2018 |
| Academy Court Management Company Limited | Professional & scientific | 2010 |
| Acai Love Ltd | Hospitality | 2025 |
| Acal BFI Central Procurement UK Limited | Administrative & support | 1969 |
| Acal BFI Group Limited | Financial services | 2021 |
| Acal BFI Holdings Limited | Financial services | 2021 |
| Acal BFI Midco 1 Limited | Financial services | 2021 |
| Acal BFI Midco 2 Limited | Financial services | 2021 |
| Acal BFI UK Limited | Wholesale & retail | 1984 |
| ACB Quantity Surveying Ltd | Professional & scientific | 2019 |
| Access Creator Ltd | Information & communication | 2024 |
| Acclaro Advisory Limited | Professional & scientific | 2012 |
| Account Sings Limited | Professional & scientific | 2017 |
| Accountant Services Ltd | Professional & scientific | 2020 |
| Accountsys Limited | Professional & scientific | 1999 |
| Accrue (Brighton) Limited | Real estate | 2026 |
| Accrue (Buchanan) Limited | Professional & scientific | 2019 |
| Accrue (Hull) Limited | Real estate | 2022 |
| Accrue (Lancaster) Ltd | Professional & scientific | 2021 |
| Accrue (Maidenhead) LLP | | 2021 |
| Accrue (Peterborough) Limited | Real estate | 2023 |
| Accrue (Quantum) LP | | 2021 |
| Accrue Capital Investments Limited | Professional & scientific | 2015 |
| Accrue Capital Limited | Professional & scientific | 2009 |
| Accrue Capital Management Limited | Professional & scientific | 2012 |
| Accrue Finance Limited | Professional & scientific | 2010 |
| Accrue Glasgow LLP | | 2019 |
| Accrue Great Haddon Limited | Professional & scientific | 2018 |
| Accrue Quantum GP Limited | Real estate | 2021 |
| Accrue Swan Holdings Limited | Real estate | 2021 |
| Accruecap (Maidenhead) Limited | Real estate | 2021 |
| Ace & Freak Ltd | Wholesale & retail | 2017 |
| Ace 4 Holdings Limited | Financial services | 2022 |
| Ace 4 Kebabs Limited | Manufacturing | 1997 |
| Ace 4 Property Limited | Construction | 2023 |
| Ace Event Partners Ltd | Administrative & support | 2025 |
| Ace Housing Ltd | Real estate | 2020 |
| Ace Residential Properties Limited | Real estate | 2020 |
| Ace Roofing and Guttering Ltd | Construction | 2025 |
| Ace Technology Solutions Limited | Information & communication | 2011 |
| Acer Rubrum Limited | Real estate | 2017 |
| Achoacho Ltd | Health & social care | 2026 |
| Acme AI & FX Limited | Information & communication | 2026 |
| Acme Stoves Limited | Administrative & support | 2023 |
| ACN IT Services Ltd | Information & communication | 2017 |
| Acorah Newco Limited | Extraterritorial | 2015 |
| Acorah Software Products Limited | Information & communication | 2000 |