| 0VERR1DE Limited | Real estate | 2020 |
| 1 Million Tattoo Studio Ltd | Other services | 2020 |
| 101 Property Hub Ltd | Real estate | 2020 |
| 12AM Capital Ltd | Financial services | 2007 |
| 1877 Investments Limited | Financial services | 2011 |
| 1AIM Asset Management Limited | Professional & scientific | 2000 |
| 295 Woodstock Road Limited | Households | 1980 |
| 3 G Legal Ltd | Professional & scientific | 2021 |
| 3D Motor Europe Limited | Wholesale & retail | 2014 |
| 3R Capital Limited | Other services | 2015 |
| 3SIXTY Creative Solutions Ltd | Professional & scientific | 2024 |
| 5 Star Properties 2021 Limited | Real estate | 2021 |
| 787 Property Ltd | Real estate | 2023 |
| 8000 CH Properties Limited | Real estate | 2022 |
| 90210 Ltd | Administrative & support | 2021 |
| A & L Convenience Stores Ltd | Wholesale & retail | 2018 |
| A & R Catering Ltd | Hospitality | 2016 |
| A & T Building Supplies Ltd | Wholesale & retail | 2024 |
| A B Owen Limited | Professional & scientific | 2003 |
| A Davies Mechanical Engineering Services Ltd | Professional & scientific | 2023 |
| A Nock Properties Limited | Households | 2016 |
| A R Transport Logistics Ltd | Transport & logistics | 2025 |
| A Team Racking Limited | Other services | 2023 |
| A W Upholstery Ltd | Other services | 2003 |
| A&A Professional Hand Car Wash & Valet Ltd | Other services | 2014 |
| A&R Body Repair and Recovery Ltd | Wholesale & retail | 2023 |
| A. Hingley Transport (Brierley Hill) Limited | Transport & logistics | 1972 |
| A.H. Franchise Ltd | Real estate | 2021 |
| A.J.T. Equipment Limited | Manufacturing | 1951 |
| A1 Motor Spares (Midlands) Ltd | Wholesale & retail | 2023 |
| A1 Rentals Limited | Administrative & support | 1994 |
| A3 Building Merchants Ltd | Real estate | 2025 |
| AA20 Properties Ltd | Real estate | 2019 |
| Abany Consulting Limited | Information & communication | 2010 |
| Abbeymore Estates Ltd | Real estate | 2012 |
| Abbott Barber Communications Limited | Professional & scientific | 2010 |
| ABC Marine Services Limited | Manufacturing | 2008 |
| ABC4SAFETYUK Limited | Professional & scientific | 2018 |
| Abdel Group Holdings Limited | Administrative & support | 2022 |
| ABG Recruitment Ltd | Administrative & support | 2019 |
| Ablet Limited | Administrative & support | 2014 |
| Abnerlit Contracting Ltd | Construction | 2016 |
| Abstergo Consultancy Limited | Professional & scientific | 2018 |
| Abstract Visions Associates Ltd | Administrative & support | 2017 |
| ABU Salman Medical Tourism Ltd | Professional & scientific | 2019 |
| Accommod Contracting Ltd | Transport & logistics | 2016 |
| Account Right Limited | Professional & scientific | 2003 |
| Accurate Accounts Limited | Professional & scientific | 1992 |
| Acer Snowmec Limited | Professional & scientific | 1992 |
| Acer Snowmec Technologies Limited | Other services | 2014 |
| Acfb Properties Limited | Real estate | 2025 |
| Aciex Ltd | Manufacturing | 2026 |
| Aciw Ltd. | Wholesale & retail | 2015 |
| ACM Training Room Ltd | Education | 2025 |
| Acme Planning & Consulting Ltd | Extraterritorial | 2021 |
| Acorn Environmental Care Limited | Administrative & support | 2012 |
| Acorns Day Care Limited | Health & social care | 2018 |
| ACR Heat Products Limited | Wholesale & retail | 2004 |
| ACS North West Ltd | Professional & scientific | 2021 |
| ACT & Recovery Ltd | Wholesale & retail | 2025 |
| Adams Carpets & Furniture Limited | Wholesale & retail | 2017 |
| Adams Furniture Ltd | Wholesale & retail | 2024 |
| ADD Mgmt Ltd | Professional & scientific | 2023 |
| Adeel's Restaurant Ltd | Hospitality | 2015 |
| Adfloor Industrial Limited | Construction | 1998 |
| ADI Scaffold Products Ltd | Manufacturing | 2012 |
| ADI Supply Limited | Administrative & support | 2003 |
| Adroit Alternatives Properties Limited | Real estate | 2004 |
| Advanced Paving & Resin Ltd | Construction | 2026 |
| Advanced Technology Partners Limited | Information & communication | 1997 |
| Advantage Finance & Leasing Limited | Financial services | 1997 |
| Advocatus Prime Ltd | Information & communication | 2024 |
| AED Roller Group Holdings Limited | Financial services | 2024 |
| AED Rollers Ltd | Manufacturing | 2002 |
| Aerbuddies Limited | Professional & scientific | 2007 |
| AF Market Shops Ltd | Wholesale & retail | 2025 |
| AFP Investment Limited | Real estate | 2025 |
| Africa Xpress Limited | Wholesale & retail | 2018 |
| AG Garage Doors Limited | Construction | 2010 |
| AG Refinery Ltd | Financial services | 2026 |
| Agapanthus Holdings Limited | Financial services | 2017 |
| Agcd Limited | Education | 2014 |
| AH4 Properties Limited | Real estate | 2023 |
| Ahad Estate Limited | Real estate | 2021 |
| Ahadme Properties Limited | Real estate | 2025 |
| Ahus Estates Ltd | Real estate | 2024 |
| Ahyanz Ltd | Wholesale & retail | 2021 |
| AI Global Security Ltd | Administrative & support | 2024 |
| AI Software Solutions Limited | Other services | 2018 |
| Aimtru Brands Limited | Extraterritorial | 2022 |
| Aimtru Limited | Wholesale & retail | 2009 |
| Airdrate Ltd | Manufacturing | 2018 |
| Aitch JP Ltd | Real estate | 2021 |
| AJ Sian Tyres Ltd | Wholesale & retail | 2025 |
| AJB Trading LLP | | 2009 |
| AJF Management Consultancy Limited | Professional & scientific | 2015 |
| AJG UK Holdings Limited | Other services | 2018 |
| AJH Business (UK) Ltd | Real estate | 2017 |
| AJH Engineering Solutions Ltd | Professional & scientific | 2020 |
| AJK Electric Heating and Plumbing Ltd | Construction | 2025 |