| Accounting Solutions Manchester LLP | | 2012 |
| Accounts & Business Solutions Limited | Professional & scientific | 2013 |
| Accounts (by MRB) Limited | Professional & scientific | 2008 |
| Accounts Direct (Accounting & Bookkeeping) Limited | Professional & scientific | 2008 |
| Accrington Vapours Ltd | Wholesale & retail | 2020 |
| Accuplan Ltd | Information & communication | 2026 |
| Accuplan Solutions Ltd | Information & communication | 2026 |
| Ace PMO Ltd | Information & communication | 2020 |
| Ace Telecommunications Limited | Professional & scientific | 1990 |
| Aceites Abril S.L. Ltd | Construction | 2025 |
| Acervo Ltd | Information & communication | 2025 |
| Aceview Estates Ltd | Real estate | 2016 |
| ACH Group Management Limited | Administrative & support | 2009 |
| Achim Drinks Limited | Wholesale & retail | 2024 |
| Achim TAL Esther Limited | Real estate | 2021 |
| Achuandsons Ltd | Construction | 2025 |
| Acme Processing Services (APS) Ltd | Administrative & support | 2023 |
| ACO ACO Ltd | Information & communication | 2025 |
| Acorn Interiors and Shopfitting Ltd | Manufacturing | 2021 |
| Acps Trustee Limited | Extraterritorial | 2017 |
| Acquella Cuisine Ltd | Hospitality | 2025 |
| Acquired Recruitment Ltd | Professional & scientific | 2024 |
| Acresbrook Limited | Extraterritorial | 1997 |
| Acrison International (UK) Limited | Manufacturing | 2009 |
| Active Estate MCR Ltd | Real estate | 2017 |
| Active Pharmacare Holdings Ltd | Financial services | 2023 |
| Active Pharmacare Ltd | Health & social care | 2015 |
| Active Pharmacare Properties Limited | Real estate | 2018 |
| Active Pharmacare Training Limited | Health & social care | 2018 |
| Active Property Group Ltd | Real estate | 2018 |
| Active Warrington CIC | Education | 2023 |
| Acumen Acquisition Limited | Financial services | 2025 |
| Acura Communications Limited | Information & communication | 2014 |
| AD Center Media Limited | Professional & scientific | 2024 |
| AD Consultancy Ltd | Health & social care | 2025 |
| AD Developments NW Ltd | Construction | 2014 |
| AD Legal Consulting Limited | Professional & scientific | 2024 |
| AD Mayoh V'Esrim Limited | Other services | 2017 |
| AD Mosai Estates Limited | Real estate | 2023 |
| AD Prop Assets Limited | Construction | 2026 |
| AD Servcom Ltd | Transport & logistics | 2026 |
| Ad-Ork Healthcare Ltd | Health & social care | 2022 |
| Adam Belhouche Limited | Professional & scientific | 2025 |
| Adams Sandwich Bar Ltd | Hospitality | 2024 |
| Adapt a Room Limited | Construction | 2019 |
| Adas Aish Kodesh (MCR) Ltd | Other services | 2025 |
| Adass Yeshurun Synagogue | Other services | 2017 |
| ADC Kanife Ltd | Real estate | 2023 |
| ADC Media LLP | | 2011 |
| Adcam TV Ltd | Arts & recreation | 2023 |
| Adcc UK Ltd | Wholesale & retail | 2024 |
| Added Detail Limited | Administrative & support | 2024 |
| Added Nominees Limited | Extraterritorial | 2004 |
| Additron Ltd | Wholesale & retail | 2024 |
| Addtract Limited | Professional & scientific | 2025 |
| Adelie Holdings Limited | Real estate | 2022 |
| Adella's Kitchen Ltd | Hospitality | 2020 |
| Adelphi Lounge Ltd | Real estate | 2024 |
| Adeptus Care Limited | Health & social care | 2004 |
| Ades Rehoboath Ltd | Health & social care | 2012 |
| Adey’S Luxury Limited | Other services | 2024 |
| ADG Stocks Ltd | Wholesale & retail | 2023 |
| ADI Network Limited | Education | 2023 |
| Adigetech Ltd | Information & communication | 2022 |
| Adinan Limited | Real estate | 2017 |
| Adjuvo (North) Support for Living Ltd | Health & social care | 2014 |
| Adjuvo Care & Support Ltd | Health & social care | 2017 |
| Adjuvo Care Group Limited | Financial services | 2018 |
| ADL Assets NW Ltd | Real estate | 2020 |
| Adler Homes Limited | Real estate | 2026 |
| ADM Protexin Limited | Manufacturing | 1973 |
| Admb Trade and Marketing Ltd | Wholesale & retail | 2019 |
| Admiral Housewares Limited | Wholesale & retail | 2002 |
| Admiralty Property Group Ltd | Real estate | 2024 |
| Adnopark Ltd | Wholesale & retail | 2013 |
| Adool Construct and Designs Limited | Construction | 2022 |
| Adrian Mitula Transport Ltd | Transport & logistics | 2024 |
| Adrian Morley Services Limited | Arts & recreation | 2015 |
| Adriatic Solutions Limited | Extraterritorial | 2021 |
| ADS and That Ltd | Professional & scientific | 2022 |
| Adspire Media Solutions Ltd | Wholesale & retail | 2022 |
| Aduol Industries Limited | Agriculture & fishing | 2021 |
| Advaitha Group PVT Ltd | Wholesale & retail | 2025 |
| Advance Management (UK) Ltd | Professional & scientific | 2013 |
| Advanced Call Center Solutions Limited | Administrative & support | 2018 |
| Advanced Robotic Technology Ltd | Professional & scientific | 2010 |
| Advanced Technology Adtech Ltd | Wholesale & retail | 2025 |
| Adventure Lounge Ltd | Other services | 2016 |
| Adventure Telecom Ltd | Information & communication | 2017 |
| Advisory People Ltd | Real estate | 2022 |
| Adzdaramola Limited | Administrative & support | 2022 |
| Adzi Trade Ltd | Construction | 2025 |
| AE Services Ltd | Hospitality | 2026 |
| Aegean Estates MCR Ltd | Real estate | 2024 |
| Aegidius Consulting Limited | Professional & scientific | 2025 |
| Aeliya Trades Ltd | Wholesale & retail | 2026 |
| AEM Pharma Limited | Wholesale & retail | 2019 |
| AEM Pro Ltd | Real estate | 2021 |
| Aerial Circus School Ltd | Arts & recreation | 2020 |
| Aeris Health Limited | Other services | 2025 |