| Adams Watkins & Co Limited | Professional & scientific | 2003 |
| Adansie Consult Ltd | Professional & scientific | 2024 |
| Adapta Climate Finance Facility Ltd | Administrative & support | 2026 |
| Adara Consulting Limited | Information & communication | 2014 |
| Adart Global Ltd | Administrative & support | 2025 |
| Addiscombe Treehouse Limited | Real estate | 2017 |
| Additionality Limited | Information & communication | 1999 |
| Addwings Expand International Ltd | Professional & scientific | 2025 |
| Adebayo Ventures Ltd | Professional & scientific | 2025 |
| Adejanproperty Limited | Real estate | 2024 |
| Adekunle & Ejenobi Investments Limited | Real estate | 2023 |
| Adem & Yildira Investment Ltd | Real estate | 2025 |
| Adeola Innovation Limited | Health & social care | 2024 |
| Adeola Media Solutions Limited | Other services | 2007 |
| Adept Security Services Limited | Administrative & support | 2023 |
| Adept Lift Technical Services EOT Limited | Administrative & support | 2024 |
| Adept Lift Technical Services Limited | Professional & scientific | 1988 |
| Adeyemi Holdings Limited | Public administration | 2025 |
| ADG Tech Ltd | Wholesale & retail | 2024 |
| Adhd Untangled Ltd | Health & social care | 2022 |
| ADHERE2 Ltd | Administrative & support | 2024 |
| Adhyams Ltd | Manufacturing | 2026 |
| Adic Vigilant Ltd | Administrative & support | 2018 |
| Adil Imaging Limited | Health & social care | 2024 |
| ADJ Contract Services Limited | Administrative & support | 2017 |
| Adjusted Thinking Limited | Information & communication | 2013 |
| ADK Constructions Ltd | Construction | 2013 |
| ADL Facades Ltd | Construction | 2014 |
| ADL Management Limited | Real estate | 2016 |
| Adonai PVT Ltd | Health & social care | 2020 |
| ADP Diamex Limited | Professional & scientific | 2004 |
| ADP Diamond Cutting Solutions Limited | Wholesale & retail | 2003 |
| ADS ( Dartford ) Ltd | Hospitality | 2025 |
| ADS Accountants Ltd | Professional & scientific | 2025 |
| ADS Facilities Limited | Construction | 2025 |
| ADS Property (Brands Hatch) Ltd | Real estate | 2022 |
| ADS Property Facilities Ltd | Construction | 2021 |
| Adshal Ltd | Professional & scientific | 2021 |
| Adun Ltd | Health & social care | 2024 |
| Adunni Botanicals Limited | Wholesale & retail | 2022 |
| Aduragbemi Limited | Health & social care | 2020 |
| Adusanko Ltd | Wholesale & retail | 2026 |
| Advance Cleaning Services Brighton Ltd | Administrative & support | 2025 |
| Advance Contracts Limited | Transport & logistics | 2006 |
| Advanced Auto Films Limited | Wholesale & retail | 2003 |
| Advanced Community Care UK Ltd | Health & social care | 2023 |
| Advanced Removals & Storage Limited | Transport & logistics | 2005 |
| Advanced Vehicle Alarms Limited | Manufacturing | 2014 |
| Advantiers Limited | Information & communication | 2011 |
| Advantys Consulting Ltd | Information & communication | 2025 |
| Adventure Race Conversions Ltd | Wholesale & retail | 2020 |
| Advocate Accounting & Consultancy Ltd | Professional & scientific | 2022 |
| Adysteel Ltd | Construction | 2019 |
| AE Supplies Ltd | Wholesale & retail | 2026 |
| AE UK Properties Ltd | Real estate | 2021 |
| Aercon Consultants Ltd | Professional & scientific | 1977 |
| Aermec UK Limited | Construction | 1995 |
| Aero Gym Ltd | Arts & recreation | 2025 |
| Aerospace Tooling Corporation Limited | Manufacturing | 2013 |
| Aerospace Tooling Limited | Manufacturing | 2007 |
| Aerospace Tooling Trustee Limited | Professional & scientific | 2021 |
| AES Contractors Ltd | Construction | 2015 |
| Aesthetic Architecture Limited | Arts & recreation | 2018 |
| AFA Flooring Ltd | Administrative & support | 2016 |
| AFC Whyteleafe Youth LLP | | 2022 |
| Aferisco Limited | Health & social care | 2021 |
| Affable Management Consultancy Limited | Professional & scientific | 2019 |
| Affik Care Limited | Health & social care | 2013 |
| Affordable Auto Hub Ltd | Wholesale & retail | 2026 |
| Affordable Bird Control Limited | Administrative & support | 2008 |
| Afio Adoley Limited | Health & social care | 2024 |
| Afpan Edward Solicitors Ltd | Professional & scientific | 2023 |
| Afrograce Foods Ltd | Wholesale & retail | 2025 |
| AFS Pharma Limited | Professional & scientific | 2011 |
| Aftermarket Wholesale Academy Ltd | Education | 2024 |
| AG Consultants QS Ltd | Construction | 2025 |
| AG Rentals (Dartford) Ltd | Other services | 2023 |
| Against ALL Odds Still Standing | Professional & scientific | 2013 |
| Agape Medical Health Care Ltd | Real estate | 2020 |
| Agate Management Services Limited | Professional & scientific | 2014 |
| AGD Glazing Ltd | Other services | 2025 |
| Agentic Multipreneurs Ltd | Professional & scientific | 2025 |
| Aggarwal Investments Limited | Real estate | 2021 |
| Agile Cyber Solutions Ltd | Other services | 2012 |
| Agility QA Ltd | Information & communication | 2018 |
| AGL Brickwork Ltd | Construction | 2019 |
| Agoboh Record's Ltd | Arts & recreation | 2024 |
| Agora Customer Contact and Experience Limited | Administrative & support | 2013 |
| Agorazo Enterprise Limited | Hospitality | 2013 |
| Agorazo Property Limited | Real estate | 2019 |
| Agricultural Holdings Ltd | Agriculture & fishing | 2011 |
| Agrs Construction Ltd | Construction | 2022 |
| AGS Global Logistics & Cargo Ltd | Transport & logistics | 2025 |
| Agso International Lawyers (U.K.) Ltd | Professional & scientific | 2015 |
| Agtec Concept Limited | Other services | 2014 |
| Agusa Ltd | Transport & logistics | 2025 |
| Ahadi Ltd | Administrative & support | 2010 |
| Ahmad & Commpany Ltd | Hospitality | 2023 |
| Ahnaf Holdings Ltd | Real estate | 2025 |
| AI Auxesis Limited | Information & communication | 2025 |