| 1 Upper Kincraig Street Ltd | Households | 2020 |
| 10 Exchange Road Management Company Limited | Extraterritorial | 2023 |
| 13THIRTEEN Solutions Ltd | Professional & scientific | 2023 |
| 16 Kingsley Road Cotham Management Company Limited | Real estate | 1987 |
| 20-20 Technologies Limited | Information & communication | 1987 |
| 21ST Century Fleet Systems Limited | Extraterritorial | 1988 |
| 21ST Century Integrated Systems Limited | Other services | 1989 |
| 21ST Century Passenger Systems Limited | Extraterritorial | 1992 |
| 21ST Century Technology Group Limited | Extraterritorial | 2000 |
| 21ST Century Technology Limited | Manufacturing | 2017 |
| 21ST. Century Crime Prevention Services Limited | Extraterritorial | 1995 |
| 3D-SERVICE Metrology Ltd | Information & communication | 2021 |
| 4B Property Limited | Households | 2013 |
| 562 Woodborough Road Management Company Limited | Households | 2003 |
| 6FT From CIC | Health & social care | 2020 |
| 7079 LLP | | 2019 |
| 72 Wood Street Limited | Households | 1994 |
| 8D Consultancy Limited | Construction | 2023 |
| A C G Shields Limited | Professional & scientific | 2015 |
| A E Payne Limited | Financial services | 2010 |
| A J Hayes Group Ltd | Real estate | 2020 |
| A J Sharpe Limited | Financial services | 2015 |
| A Stewart GAS Services Ltd | Construction | 2026 |
| A.D.R Property Limited | Real estate | 2020 |
| A2 DBA Services Ltd | Information & communication | 2011 |
| AA Level Quality Textiles Limited | Wholesale & retail | 2023 |
| AA Medical Services Limited | Health & social care | 2019 |
| Abbey Extrusions Limited | Manufacturing | 1985 |
| Abbey Homes Estate Agents Limited | Extraterritorial | 2025 |
| Abbey Lettings & Property Management Specialists Ltd | Real estate | 2008 |
| Abbey Lettings & Sales Limited | Extraterritorial | 2016 |
| Abbotsford Property Management Limited | Households | 2008 |
| Abhirush Limited | Health & social care | 2012 |
| AC Minds Ltd | Health & social care | 2020 |
| Accordia Investments Ltd | Wholesale & retail | 2001 |
| Ace Glass (Southern) Limited | Wholesale & retail | 2010 |
| Ace of Drinks Ltd | Wholesale & retail | 2021 |
| Acrk Media Ltd | Arts & recreation | 2022 |
| ACS (UK) Consulting Limited | Professional & scientific | 2004 |
| ACS Hospitality Ltd | Hospitality | 2023 |
| Acuity International Consulting Ltd | Professional & scientific | 2020 |
| Adelboden Holdings Limited | Construction | 2008 |
| Adfix Ltd | Professional & scientific | 2021 |
| ADJ Ventures Ltd | Transport & logistics | 2016 |
| ADM Support Services Limited | Administrative & support | 2013 |
| Admar Investments Limited | Financial services | 2019 |
| Advance Insurance Services (Midlands) Ltd | Financial services | 2008 |
| Advanced Masonry Solutions Ltd | Construction | 2012 |
| Advantage HR Solutions Limited | Professional & scientific | 2024 |
| Aerofields Limited | Wholesale & retail | 1997 |
| Aeschi Investments Limited | Real estate | 2008 |
| Aeternum Aesthetics Limited | Health & social care | 2016 |
| Agile Engineering Group Limited | Professional & scientific | 2025 |
| Agilefinanceuk Ltd | Professional & scientific | 2021 |
| AHT Logistics Ltd | Transport & logistics | 2001 |
| AHT Teak Ltd | Agriculture & fishing | 2019 |
| AJ Contract Maintenance Limited | Manufacturing | 2023 |
| AJ Living Ltd | Households | 2025 |
| AJ Network Consulting Limited | Information & communication | 2014 |
| AJH Construction & Utilities Ltd | Construction | 2021 |
| AJR Software Ltd | Information & communication | 2026 |
| AK Dining Ltd | Hospitality | 2025 |
| Akuvi Enterprises Limited | Wholesale & retail | 2025 |
| AL3RT Fire & Security Ltd | Administrative & support | 2022 |
| Alan Archer Property Services Ltd | Construction | 2026 |
| Aldous of Dereham Limited | Real estate | 2003 |
| Alert Imagination Ltd | Hospitality | 2024 |
| Alexander Wooff Associates Limited | Professional & scientific | 2017 |
| Alice Rose Bridal (Ashby) Ltd | Wholesale & retail | 2018 |
| Alison Victoria Limited | Wholesale & retail | 2005 |
| Alison Yelland Consulting Limited | Financial services | 2022 |
| ALL Dawn Homes Ltd | Financial services | 2013 |
| Alleco Energy Installers Limited | Construction | 2022 |
| Allegra Music Limited | Education | 2004 |
| Allen's Autocare Limited | Wholesale & retail | 2009 |
| Alphatec Computers Ltd | Information & communication | 2016 |
| Alton Power (2014) Limited | Energy | 2014 |
| Alvarium Investment Managers (UK) LLP | | 2006 |
| AM Domestic Builds Limited | Construction | 2025 |
| Amalgamated Steel and Fasteners Ltd | Wholesale & retail | 2019 |
| Amb.Apt Limited | Real estate | 2022 |
| Amber Security and Protection Limited | Administrative & support | 2025 |
| Amcol Services Limited | Health & social care | 2023 |
| Amima Technology Ltd | Information & communication | 2012 |
| Ampj Commercial Properties Limited | Administrative & support | 2013 |
| Amstech Consulting Limited | Information & communication | 2017 |
| Amtech Building Solutions Limited | Construction | 2022 |
| Andy Elliott (London) Limited | Other services | 2015 |
| Andy J Smith Consulting Services Limited | Professional & scientific | 2013 |
| Annapurnavm Ltd | Health & social care | 2012 |
| Anne Bose Limited | Professional & scientific | 2022 |
| Anpr Data Limited | Administrative & support | 2023 |
| Ansh Infotech Ltd | Information & communication | 2015 |
| Anya Designs Limited | Arts & recreation | 2017 |
| Anyway Anyday Couriers Ltd | Transport & logistics | 2007 |
| AP Engineers & Plant Ltd | Manufacturing | 2020 |
| AP Implementation Services Limited | Professional & scientific | 2023 |
| APEXPRODUCTS123 Ltd | Wholesale & retail | 2026 |
| AR Financial Advice Limited | Financial services | 2019 |
| AR Meditech Ltd | Health & social care | 2017 |