| A S Property Assets Ltd | Real estate | 2023 |
| A Shaida Ltd | Health & social care | 2010 |
| A Square Restaurants Ltd | Hospitality | 2023 |
| A to Z Films Limited | Information & communication | 2014 |
| A&D Interiors Ltd | Construction | 2020 |
| A&H Building Maintenance Ltd | Administrative & support | 2022 |
| A&O DRY Lining Ltd | Construction | 2014 |
| A-Star Education Services Ltd | Education | 2023 |
| A-Trade Solutions Ltd | Extraterritorial | 2020 |
| A. Andrews Limited | Arts & recreation | 2019 |
| A.G. Reed Limited | Construction | 2016 |
| A.P Focus Plumbing and Heating Limited | Construction | 2016 |
| A.R. Watson Building Contractors Limited | Construction | 1996 |
| A.S.A.P Construction Ltd. | Construction | 1988 |
| A.S.H UK Enterprise Ltd | Administrative & support | 2026 |
| A.T.Solutions (London) Ltd | Professional & scientific | 2023 |
| A2B Recruitment Solutions Limited | Health & social care | 2016 |
| A2DD-HP Boston Road LLP | | 2020 |
| A2URE Holdings Limited | Financial services | 2021 |
| A2URE Property Holdings Limited | Real estate | 2024 |
| AA Gears Ltd | Information & communication | 2022 |
| AAB Holdings Ltd | Real estate | 2016 |
| AAC Corporation Limited | Administrative & support | 2025 |
| AAH Investment Management Ltd | Extraterritorial | 2013 |
| Aanderson Interiors Ltd | Construction | 2025 |
| Aarckle Associates Limited | Professional & scientific | 2013 |
| Aarkz Design Limited | Professional & scientific | 2014 |
| Aavon Care Limited | Health & social care | 2025 |
| AB ENT Services Limited | Health & social care | 2010 |
| Abacus Childrens Stores Limited | Wholesale & retail | 2004 |
| Abacus Print Limited | Manufacturing | 2004 |
| Abaqs AI Limited | Information & communication | 2026 |
| Abbey Care Services Limited | Health & social care | 2016 |
| Abbey Personnel Limited | Administrative & support | 1998 |
| Abbey Staff Agency Limited | Administrative & support | 2025 |
| Abbey Total Community Care Limited | Health & social care | 2023 |
| Abbey Uplands Care Home Limited | Health & social care | 2023 |
| Abbotrange Limited | Construction | 1995 |
| Abbots Inns Limited | Hospitality | 2019 |
| Abee Asbestos Removal Ltd | Water & waste | 2018 |
| ABI Pubs Ltd | Hospitality | 2014 |
| Abineysh Limited | Administrative & support | 2024 |
| Abiodun Adebanjo Productions Limited | Hospitality | 2025 |
| Ableoak Limited | Real estate | 1988 |
| Abmc Properties Limited | Real estate | 2025 |
| ABN Catering Limited | Hospitality | 2018 |
| Abode (Woodford) Ltd | Real estate | 2009 |
| Abode Estate Agency Limited | Real estate | 2017 |
| Above & Beyond Roofing Specialists Limited | Construction | 2021 |
| Abridge Home Improvements Limited | Administrative & support | 2022 |
| Absolute Training Ltd | Health & social care | 2006 |
| Absolutely Admin Solutions Ltd | Professional & scientific | 2022 |
| Academy Management Company (London) Limited | Real estate | 1991 |
| Acc&C Trading Limited | Construction | 2016 |
| Access International Security Limited | Construction | 2003 |
| Access Recycle Ltd | Extraterritorial | 2015 |
| Accessoride Limited | Wholesale & retail | 2026 |
| Ace Electrical London Ltd | Construction | 2021 |
| Ace Estates London Ltd | Construction | 2025 |
| Ace Roofing and Building Limited | Construction | 2016 |
| Ace Roofing Solutions Limited | Construction | 2020 |
| Achiaa Ltd | Health & social care | 2022 |
| Achieveability Limited | Education | 2010 |
| Ackles Ltd | Other services | 2026 |
| ACL (1997) Limited | Extraterritorial | 1968 |
| Acorn & GH (RF) Limited | Administrative & support | 2017 |
| Acorns Childcare Ltd | Health & social care | 2026 |
| ACT Construction Solutions Ltd | Professional & scientific | 2023 |
| ACT Tech Solutions Ltd | Manufacturing | 2025 |
| Acuutech Limited | Information & communication | 1996 |
| Acuutech Select Ltd | Information & communication | 2015 |
| Adam & Bull Ltd | Wholesale & retail | 2006 |
| Adano's Ltd | Hospitality | 2021 |
| ADD Colours Supplies Ltd | Wholesale & retail | 2025 |
| ADE Property Ltd | Real estate | 2021 |
| Adeliza Capital Ltd | Financial services | 2023 |
| Adesso Tech Limited | Professional & scientific | 2015 |
| Adiliana Limited | Construction | 2024 |
| Adjacency Ltd | Information & communication | 2014 |
| ADL Air Conditioning Ltd | Construction | 2020 |
| Adlove Ltd. | Information & communication | 2013 |
| ADP Accounting Services UK Limited | Professional & scientific | 2022 |
| ADR Investment Properties Limited | Real estate | 2025 |
| Adrian Bourne Limited | Other services | 2015 |
| Adrian Ciulin Ltd | Transport & logistics | 2019 |
| ADS Chauffeur & Security Services Ltd | Transport & logistics | 2013 |
| ADS Training & Consultancy Limited | Professional & scientific | 2020 |
| Adsa Properties UK Ltd | Real estate | 2020 |
| Advance Building Supplies Limited | Real estate | 1999 |
| Advanced Rope Access Solutions Ltd | Construction | 2024 |
| Advent Developments Corporation Limited | Construction | 2002 |
| Ady.Ro Ltd | Administrative & support | 2011 |
| AE Coaching Limited | Other services | 2023 |
| Aegis Securities Limited | Administrative & support | 2021 |
| Aekiss Ltd | Other services | 2016 |
| Aero Vision Labs Ltd | Professional & scientific | 2025 |
| Aeropak (Chemical Products) Limited | Manufacturing | 1980 |
| Aesthetics & Co by Aston Ltd | Other services | 2022 |
| Affilab Ltd | Information & communication | 2025 |
| Affordable Housing GHL Limited | Real estate | 2024 |