| 63 QG Management Company Limited | Households | 2021 |
| 66COBO Ltd | Wholesale & retail | 2019 |
| 688 Pinner Road Management Company Limited | Households | 2020 |
| 6TH Dimension Ltd | Construction | 2017 |
| 7 Deeds Ltd | Wholesale & retail | 2024 |
| 75 Murray Road Residents Management Limited | Households | 1969 |
| 77 Hanworth Road Ltd | Real estate | 2016 |
| 7ARCH Ltd | Information & communication | 2023 |
| 7T Leases Limited | Real estate | 2023 |
| 7T Properties Limited | Real estate | 2021 |
| 83 Barry Road Dulwich Ltd | Households | 2021 |
| 89 High Street (Management) Limited | Professional & scientific | 1988 |
| 9 Connaught Road Limited | Construction | 2018 |
| 9 Woodchurch Road Limited | Real estate | 2022 |
| 97HSW Limited | Real estate | 2022 |
| A & D UK Ltd | Construction | 2006 |
| A & M London Ltd | Real estate | 2026 |
| A & R Retailer Ltd | Wholesale & retail | 2024 |
| A and Brothers Ltd | Administrative & support | 2023 |
| A Build & Construction Ltd | Construction | 2025 |
| A Certain Everything Limited | Professional & scientific | 2018 |
| A D Accountancy Ltd | Professional & scientific | 2017 |
| A Education Ltd | Education | 2022 |
| A Greener Festival Ltd | Information & communication | 2008 |
| A Husain Limited | Health & social care | 2009 |
| A I Squared Limited | Information & communication | 2024 |
| A J Lindsay Ltd | Professional & scientific | 2026 |
| A Johns Associates Ltd | Administrative & support | 2017 |
| A K IT Consultancy Services Ltd | Information & communication | 2020 |
| A M Produce Limited | Wholesale & retail | 1993 |
| A Mohamed Ltd | Professional & scientific | 2019 |
| A N Estates Ltd | Real estate | 2011 |
| A R Business Services (UK) Limited | Professional & scientific | 2013 |
| A S Inventories Ltd | Administrative & support | 2013 |
| A Slice of Nice Ltd | Manufacturing | 2011 |
| A Star Academics Ltd | Manufacturing | 2025 |
| A Star Foods Limited | Professional & scientific | 2013 |
| A T Doan Property Limited | Real estate | 2022 |
| A Time a Place a Story Limited | Extraterritorial | 2019 |
| A Touch of Sienna Limited | Information & communication | 2024 |
| A Vadher Ltd | Real estate | 2011 |
| A&3A Ltd | Information & communication | 2023 |
| A&A Accommodation Limited | Real estate | 2025 |
| A&B Modi Ltd | Real estate | 2017 |
| A&E Facades Ltd | Construction | 2020 |
| A&E Property Solutions Limited | Real estate | 2019 |
| A&E Wealth Solutions Limited | Financial services | 2016 |
| A&N Building Design Limited | Construction | 2025 |
| A&P Ferns Limited | Wholesale & retail | 2026 |
| A&R Building Services Limited | Construction | 2015 |
| A&R Home Developments Limited | Construction | 2019 |
| A&V Limited | Construction | 2024 |
| A&Y Investment Holdings Limited | Financial services | 2024 |
| A-Luxe Production Ltd | Administrative & support | 2025 |
| A-One Foods (London) Ltd | Hospitality | 2022 |
| A.A.K (Marlow) Limited | Real estate | 2025 |
| A.I.V Construction Ltd | Construction | 2014 |
| A.J.M. Mansell Holdings Limited | Financial services | 2016 |
| A.J.M.Mansell Limited | Wholesale & retail | 1961 |
| A.K Health Group Ltd | Health & social care | 2026 |
| A.L.E.O Creative Ltd | Wholesale & retail | 2023 |
| A.M Meer Limited | Extraterritorial | 2021 |
| A.T.S.I. Limited | Manufacturing | 2000 |
| A.W. Optical Services Limited | Health & social care | 2010 |
| A2Z Estate Management Ltd | Real estate | 2025 |
| AA IT Consultancy Ltd | Information & communication | 2010 |
| AA Piri Piri Limited | Hospitality | 2022 |
| AAA OC Limited | Professional & scientific | 2024 |
| AAA Retail London Ltd | Financial services | 2026 |
| AAC Developments Ltd | Construction | 2014 |
| Aadhyan Global Ltd | Wholesale & retail | 2026 |
| Aaditya Adventures & Tours Ltd | Hospitality | 2024 |
| AAH Hatch END Limited | Wholesale & retail | 2020 |
| Aakriti Limited | Real estate | 2014 |
| Aamsa Investments Limited | Real estate | 2021 |
| AAR Fruits & VEG Ltd | Wholesale & retail | 2026 |
| Aarahi Ltd | Wholesale & retail | 2021 |
| Aarav Associates Limited | Professional & scientific | 2013 |
| Aareeva Properties Limited | Real estate | 2024 |
| Aarjai Ltd | Financial services | 2025 |
| Aarohi Capital Ltd | Financial services | 2026 |
| Aarthvedaa Ltd | Information & communication | 2025 |
| Aarya Solutions Limited | Information & communication | 2013 |
| Aasai Ltd | Hospitality | 2024 |
| Aavya Properties Ltd | Real estate | 2020 |
| Aayan Investments Limited | Real estate | 2019 |
| AB Construct Solutions Ltd | Construction | 2026 |
| Abacus Care & Support Limited | Health & social care | 2019 |
| Abalone Creations Limited | Wholesale & retail | 2016 |
| Abbi Consulting Limited | Professional & scientific | 2021 |
| Abbott Electrical Limited | Construction | 2023 |
| ABC Smile Ltd | Health & social care | 2016 |
| Abercorn Capital Limited | Financial services | 2010 |
| Aberdare Capital Limited | Real estate | 2025 |
| Abglobal Trading Ltd | Wholesale & retail | 2024 |
| Abhi Retail Ltd | Wholesale & retail | 2026 |
| Abigail Hazell Garden Design Limited | Professional & scientific | 2012 |
| Abinitio Properties Limited | Construction | 2015 |
| ABL Corporate Limited | Financial services | 2025 |
| ABM Accountancy Limited | Professional & scientific | 1995 |