| Aberystwyth Driving School Limited | Other services | 2010 |
| Abetra Private Limited | Wholesale & retail | 2025 |
| Abigail Warner Limited | Manufacturing | 2012 |
| Abikeh Ltd | Health & social care | 2021 |
| Abiljo Excavator Services Limited | Manufacturing | 1979 |
| ABJ 29 Ltd | Administrative & support | 2025 |
| ABJ 30 Ltd | Hospitality | 2026 |
| ABK Manufacturing Limited | Manufacturing | 2008 |
| Ably IT Ltd | Information & communication | 2015 |
| ABM Commercial Cleaning Limited | Administrative & support | 2022 |
| ABM Deep Clean Ltd | Administrative & support | 2025 |
| ABM Utility Solutions Ltd | Administrative & support | 2006 |
| Abnoba Farm and Equine Ltd | Agriculture & fishing | 2026 |
| Abnu-Sb UK Limited | Health & social care | 2022 |
| Abnu-Sd Limited | Health & social care | 2023 |
| Abode Ventures Ltd | Real estate | 2024 |
| About Backs and Bones Limited | Health & social care | 2006 |
| ABR Developments Ltd | Construction | 2026 |
| Abram Hitech Limited | Information & communication | 2024 |
| Abre Properties Ltd | Real estate | 2025 |
| ABS Constructions (London) Ltd | Construction | 2018 |
| ABS Force Limited | Administrative & support | 2026 |
| ABS Medical Ltd | Health & social care | 2023 |
| Absm Solutions Limited | Information & communication | 2013 |
| Absolute Holdings Limited | Extraterritorial | 2021 |
| Absolute IT Asset Disposals Limited | Water & waste | 2016 |
| Absolute Networks Limited | Wholesale & retail | 2003 |
| Absolute Pattern and Toolmakers Limited | Manufacturing | 2015 |
| Absolute Payments Limited | Other services | 2018 |
| Absolute Sauce Ltd | Wholesale & retail | 2023 |
| Absolute Window Cleaning Services Limited | Administrative & support | 2019 |
| Abstrakt Sounds Ltd | Arts & recreation | 2018 |
| Abuss Limited | Professional & scientific | 2012 |
| AC Azure Management Ltd | Construction | 2023 |
| AC Building Contracts Limited | Construction | 2021 |
| AC Car Group Limited | Professional & scientific | 2007 |
| AC Cars (England) Ltd | Wholesale & retail | 2016 |
| AC Cars Limited | Professional & scientific | 2004 |
| AC Cars Manufacturing Ltd | Professional & scientific | 2007 |
| AC Green Technology Limited | Professional & scientific | 2010 |
| AC Management Group Ltd | Real estate | 2023 |
| Ac&Co Ltd | Professional & scientific | 2016 |
| Ac-Dc Sales Services Ltd | Professional & scientific | 2024 |
| ACA Accountancy Services Limited | Administrative & support | 2023 |
| ACA Consultants Ltd | Professional & scientific | 2019 |
| ACA Estates Ltd | Real estate | 2019 |
| ACA Recruitment Services Limited | Administrative & support | 2022 |
| Acacia Barnes Ltd | Information & communication | 2016 |
| Acacia Creatives Ltd | Administrative & support | 2019 |
| Academic Let.Co.Uk Limited | Real estate | 2002 |
| Academy of Timeless Beauty & Nails Ltd | Other services | 2024 |
| Acam Technology Limited | Manufacturing | 1997 |
| ACB Home Improvements Ltd | Construction | 2007 |
| ACB Investments Limited | Real estate | 2014 |
| Acbromley Properties Limited | Real estate | 2025 |
| ACC Accountancy Ltd | Professional & scientific | 2011 |
| ACC Hair Ltd | Other services | 2019 |
| ACC Property 2017 Limited | Real estate | 2017 |
| ACC Services (Derby) Ltd | Transport & logistics | 2005 |
| Accasa Ltd | Real estate | 2025 |
| Accelerate Physiotherapy Ltd | Health & social care | 2016 |
| Accept Consulting Ltd | Professional & scientific | 2012 |
| Access 2 Advice Community Interest Company | Professional & scientific | 2007 |
| Access Care Solutions Limited | Administrative & support | 2019 |
| Acclimatise Management Limited | Financial services | 2015 |
| Accommtec Ltd | Information & communication | 2014 |
| Accomplish Investments Ltd | Real estate | 2023 |
| Accountancy & Advice for Small Businesses Limited | Professional & scientific | 1993 |
| Accountancy 4 Success Limited | Professional & scientific | 2014 |
| Accountancy 4 Tax Savings Limited | Professional & scientific | 2014 |
| Accountancy 4 Wealth Limited | Professional & scientific | 2014 |
| Accountify Global Limited | Professional & scientific | 2025 |
| Accounting & Taxation Advisory Firm Limited | Professional & scientific | 2025 |
| Accounting Bliss Ltd | Professional & scientific | 2024 |
| Accounting Solutions Derby Limited | Professional & scientific | 2023 |
| Accounts & Tax Assist Ltd | Professional & scientific | 2019 |
| Accounts Ninjas Ltd | Professional & scientific | 2020 |
| Accountspoint Limited | Professional & scientific | 2012 |
| Accrofab (Derby) Limited | Manufacturing | 2018 |
| Accrofab Holdings Limited | Financial services | 2023 |
| Accrofab Investments Limited | Financial services | 2023 |
| Accutags Ltd | Manufacturing | 2026 |
| Acdc Transport Ltd | Transport & logistics | 2016 |
| Ace 2009 Limited | Administrative & support | 2009 |
| Ace Bookings Limited | Administrative & support | 2015 |
| Ace Case Accessories Ltd | Wholesale & retail | 2015 |
| Ace Discounts Ltd | Wholesale & retail | 2022 |
| Ace Equipment Ltd | Professional & scientific | 2025 |
| Ace Food Supplies Limited | Wholesale & retail | 2023 |
| Ace Garden Transformations Ltd | Administrative & support | 2026 |
| Ace Home Investments Ltd | Real estate | 2026 |
| Ace of Fades Derby Limited | Other services | 2020 |
| Ace PFS Ltd | Construction | 2018 |
| Ace Shooting Limited | Wholesale & retail | 2015 |
| Ace Tennis Camps (Ardingly College) Limited | Administrative & support | 2012 |
| Ace Tennis Camps Limited | Arts & recreation | 2009 |
| Acedeal Limited | Administrative & support | 2001 |
| Acedes Holdings Ltd | Administrative & support | 1987 |
| Acer Property Investments Limited | Real estate | 2018 |
| ACG Property Lettings & Management Ltd | Households | 2021 |