| 108 Therapy Limited | Health & social care | 2023 |
| 13-15 Lord Nelson Street RTM Company Ltd | Households | 2013 |
| 18650 UK Ltd | Wholesale & retail | 2017 |
| 1ST GTI Limited | Wholesale & retail | 1995 |
| 28 Storeys Development and Brickwork Limited | Construction | 2024 |
| 29 Fingers Limited | Arts & recreation | 2012 |
| 3-WISE Limited | Administrative & support | 2002 |
| 339 Investments Ltd | Real estate | 2024 |
| 35TV Ltd | Information & communication | 2016 |
| 4 Acres SW Limited | Agriculture & fishing | 1996 |
| 545 Resourcing Ltd | Professional & scientific | 2023 |
| 60H Limited | Professional & scientific | 2025 |
| 62 Waverley Freehold Limited | Households | 2019 |
| 80H Consulting Limited | Information & communication | 2011 |
| 9 Redburn Street Limited | Professional & scientific | 2006 |
| A & C Pearson Properties Limited | Real estate | 2023 |
| A & D Scott Public House Limited | Hospitality | 2003 |
| A & G Sports Limited | Education | 2011 |
| A Cordery (Cars) Limited | Manufacturing | 2013 |
| A Cordery Limited | Construction | 2007 |
| A H Eales Limited | Administrative & support | 2002 |
| A J Flower Limited | Administrative & support | 2018 |
| A&M Property Ventures Group Ltd | Real estate | 2026 |
| A&S Stanford Limited | Professional & scientific | 2023 |
| A-Link Holdings Limited | Real estate | 2021 |
| A. and R. Porter Limited | Construction | 1970 |
| A. Sewell Limited | Construction | 2003 |
| A.D.E.P.T. Maintenance Limited | Construction | 2003 |
| A.W.Porter & SON Limited | Wholesale & retail | 2008 |
| AA Contractors Limited | Construction | 2015 |
| AB Facilities Management Ltd | Construction | 2026 |
| AB Fencing Ltd | Construction | 2026 |
| AB Group Solutions Ltd | Water & waste | 2026 |
| Abacus Hill Limited | Information & communication | 2006 |
| Abacus HR Ltd | Administrative & support | 2006 |
| Abbj Properties Ltd | Real estate | 2022 |
| ABC Bespoke QS Ltd | Professional & scientific | 2017 |
| ABL Property Investment Limited | Real estate | 2019 |
| Absolute Care and Training Solutions Ltd | Health & social care | 2013 |
| Abvr Finance Limited | Financial services | 2017 |
| Abvr Group Limited | Financial services | 2017 |
| Abvr Holdings Limited | Wholesale & retail | 2017 |
| AC Medical Consultancy Limited | Real estate | 2013 |
| Ace Finance Consulting Ltd | Professional & scientific | 2023 |
| Active Edge (Nutrition) Limited | Wholesale & retail | 2005 |
| Adam Johnson Advisory Limited | Professional & scientific | 2017 |
| Adbod Design Limited | Information & communication | 2009 |
| ADL Admin Assist Limited | Professional & scientific | 2015 |
| Admiral Park (Block 6) Residents Management Company Limited | Households | 2023 |
| Admiral Park (Tongham) Management Company Limited | Households | 2021 |
| Adriananyata Ltd | Other services | 2020 |
| Adult Child Health and Environmental Support Ltd | Professional & scientific | 2023 |
| Aduunyo Records Limited | Information & communication | 2025 |
| Advance Nutra Consulting Ltd | Wholesale & retail | 2026 |
| AEB Catering & Events Ltd | Hospitality | 2023 |
| Aesthetic Simone Limited | Other services | 2023 |
| Affiliated Film Services Ltd | Information & communication | 2024 |
| Affinity Scaffolding Limited | Construction | 2016 |
| Affortis Ltd | Other services | 2018 |
| Afterlife Care Limited | Transport & logistics | 2023 |
| AGENT8 Design Limited | Professional & scientific | 2003 |
| Agnosco Capital Limited | Professional & scientific | 2012 |
| AGX Holdings Limited | Manufacturing | 1999 |
| AH Practice Holdings Limited | Financial services | 2019 |
| AH Practice Management Limited | Health & social care | 2021 |
| AHK Andwell LLP | | 2014 |
| AHK Andwell Management Limited | Real estate | 2022 |
| AHM Vehicles Ltd | Wholesale & retail | 2024 |
| AI Skouted ME Limited | Information & communication | 2026 |
| Air Horse One Ltd | Administrative & support | 2024 |
| Air Management Solutions (AMS) Ltd | Professional & scientific | 2019 |
| Air Safety Matters Limited | Professional & scientific | 2012 |
| AJ Homes Construction UK Ltd | Construction | 2025 |
| Aj-Heating & Plumbing Solutions Limited | Construction | 2019 |
| AJC Carpentry Southern Limited | Construction | 2011 |
| AJC Management Consulting Ltd | Professional & scientific | 2019 |
| AK Financial Advisers Holdings Limited | Financial services | 2022 |
| AL Coachworks Ltd | Wholesale & retail | 2014 |
| Alanbrooke Close Limited | Real estate | 1999 |
| Alastair Young Limited | Professional & scientific | 2013 |
| Albert's Cleaning Co Ltd | Administrative & support | 2018 |
| Alex Maher Books Ltd | Information & communication | 2022 |
| Alignfirst Limited | Information & communication | 2015 |
| Alimera Sciences Limited | Administrative & support | 2012 |
| Alliance Management Services Ltd. | Professional & scientific | 1988 |
| ALP Property Services (Harmer Street) Limited | Construction | 2016 |
| Alpa Medical Ltd | Professional & scientific | 2016 |
| Alpa Simulation Limited | Other services | 2020 |
| Alpha 2 Zulu Construction Ltd | Construction | 2022 |
| Alpha Drtv Limited | Wholesale & retail | 2016 |
| Alpine Huts Ltd | Hospitality | 2020 |
| Alta SOL Limited | Wholesale & retail | 2024 |
| Altbeta Consulting Limited | Professional & scientific | 2023 |
| Altor Wealth Management LLP | | 2016 |
| Alture Investments Limited | Real estate | 2025 |
| AMART4U Limited | Wholesale & retail | 2019 |
| Amber Rugs Limited | Wholesale & retail | 2013 |
| Amchu Film Ltd | Information & communication | 2023 |
| AMI Care Ltd | Health & social care | 2022 |
| Amiante STR Ltd | Professional & scientific | 2012 |