| AKR Motor Company Limited | Wholesale & retail | 2017 |
| Akshutters Ltd | Manufacturing | 2018 |
| Akus.Collection Limited | Wholesale & retail | 2026 |
| AL & Eastwest Consulting Ltd | Professional & scientific | 2018 |
| AL Civil Engineering Ltd | Construction | 2021 |
| Alain Sign Racing Limited | Arts & recreation | 2016 |
| Alarm-Tech Installations Limited | Construction | 2002 |
| Alcapi Limited | Professional & scientific | 2019 |
| Alcc Limited | Professional & scientific | 2020 |
| Alchemy 3 Ltd | Real estate | 2019 |
| Alchemy Fitness Ltd | Arts & recreation | 2011 |
| Alco Estates Southern Limited | Real estate | 2025 |
| Alco Landscapes Ltd | Construction | 2025 |
| Alcomoto Holdings Limited | Financial services | 2026 |
| Alcomoto Limited | Wholesale & retail | 2022 |
| Aldershot Group Limited | Financial services | 2026 |
| Aldershot Project Ltd | Real estate | 2026 |
| Alderson Aerospace Consulting Limited | Professional & scientific | 2025 |
| Aldhouse Holdings Ltd | Financial services | 2024 |
| Aleri Beverage Ltd | Wholesale & retail | 2011 |
| Alessandro Rabottini Limited | Arts & recreation | 2022 |
| Alexa Pro Tint Limited | Wholesale & retail | 2025 |
| Alexander Justin Investments Ltd | Financial services | 2022 |
| Alexandra Harris Ltd | Other services | 2025 |
| Alexandra Tandy Limited | Professional & scientific | 2010 |
| ALF Accounting Limited | Professional & scientific | 2008 |
| Alhaqiqa - KA Limited | Health & social care | 2024 |
| ALI D'Amario Psychology Limited | Education | 2024 |
| ALI Hussain Citizen Advice Security Martial Arts Limited | Extraterritorial | 2021 |
| Alicja Property Ltd | Real estate | 2025 |
| Alira Ltd | Information & communication | 2025 |
| Alisco Eco Developments Limited | Construction | 2025 |
| ALL Aboard Ltd | Administrative & support | 2010 |
| ALL About Animals Ltd | Other services | 2024 |
| ALL About Beauty & Aesthetics Ltd | Other services | 2017 |
| ALL About Paving Ltd | Other services | 2018 |
| ALL Around the Home Ltd | Construction | 2011 |
| ALL Catered 4 Limited | Hospitality | 2025 |
| ALL Region Access Ltd | Professional & scientific | 2026 |
| ALL Round Roofing Ltd | Construction | 2023 |
| ALL Seasons Hub Ltd | Wholesale & retail | 2025 |
| ALL Styles Consultants Limited | Professional & scientific | 2012 |
| ALL Supplies Ltd | Wholesale & retail | 2025 |
| Allan Property Investments Limited | Real estate | 2016 |
| Allcotts Yard Limited | Real estate | 2025 |
| Allen and SON Vehicle Repairs Ltd | Wholesale & retail | 2023 |
| Alliance Acquisitions Ltd | Wholesale & retail | 2011 |
| Allywags Ltd | Professional & scientific | 2014 |
| Alma Property Holdings Limited | Real estate | 2024 |
| Almafiera Limited | Administrative & support | 2025 |
| Almahmoud Ltd | Health & social care | 2025 |
| ALP Marquee Ltd | Administrative & support | 2024 |
| Alpaca Holdings Limited | Financial services | 2020 |
| Alpha Technical Recruitment Ltd | Administrative & support | 2012 |
| Alpha-Butter Ltd | Manufacturing | 2025 |
| Alphago Consulting Limited | Information & communication | 2022 |
| ALS Business Support Limited | Administrative & support | 2021 |
| ALS Creators Limited | Administrative & support | 2025 |
| Alteva Digital Limited | Extraterritorial | 2019 |
| Altius Sounds Ltd | Wholesale & retail | 2024 |
| Alto Star Ltd | Information & communication | 2024 |
| Altunatmaz Jewellery Limited | Financial services | 2025 |
| Alturex Capital Limited | Financial services | 2025 |
| Alver IT Solutions Ltd | Information & communication | 2025 |
| Always Adding Value Ltd | Information & communication | 2022 |
| Always Wright Mortgages Limited | Financial services | 2019 |
| ALX Digital Solutions Ltd | Information & communication | 2025 |
| ALZ USA Ltd | Arts & recreation | 2023 |
| AM Events Decorator Ltd | Information & communication | 2025 |
| AM Facades Limited | Construction | 2024 |
| AM2L Rentals Ltd | Real estate | 2018 |
| AM5 Solutions Limited | Wholesale & retail | 2019 |
| Amaana Homes Limited | Real estate | 2019 |
| Amanda Monk Limited | Arts & recreation | 2008 |
| Amba Dockside Holdings Limited | Financial services | 2013 |
| Amba Dockside Logistics Limited | Transport & logistics | 2014 |
| Amba Dockside Technology Ltd | Manufacturing | 2001 |
| Amba Occupational Health Limited | Health & social care | 2009 |
| Ambi Energy Ltd | Households | 2025 |
| Amblerock Ltd | Administrative & support | 2020 |
| Ambro Building Services Limited | Construction | 2004 |
| Amersham Film School Limited | Education | 2024 |
| AMH Electric Ltd | Construction | 2019 |
| Amicus Training Limited | Education | 2014 |
| Ammi Styling Ltd | Professional & scientific | 2014 |
| Amore Life Limited | Professional & scientific | 2025 |
| Amore Mortgages Limited | Financial services | 2025 |
| Amore Renewables Limited | Professional & scientific | 2025 |
| Amore Topco Limited | Financial services | 2025 |
| Amott Tree Surgery Ltd | Agriculture & fishing | 2012 |
| Amour Recruitment Solutions Ltd | Administrative & support | 2013 |
| AMT Business Solutions Ltd | Professional & scientific | 2024 |
| Amtuning Limited | Wholesale & retail | 2019 |
| AMW Health & Safety Services Limited | Administrative & support | 2003 |
| AMY Larkin Limited | Other services | 2015 |
| Anandra Limited | Information & communication | 2013 |
| Anavo Attorneys Limited | Professional & scientific | 2024 |
| ANC Global Ltd | Professional & scientific | 2020 |
| Anchor-Uk Ltd | Extraterritorial | 2026 |
| Anchorstone Retail Ltd | Wholesale & retail | 2026 |