| 10 and 12 ST Stephen's Road Management Company Limited | Households | 2003 |
| 100M Limited | Information & communication | 2005 |
| 17-31 Riverside Road Management Company Limited | Real estate | 2016 |
| 2I Accountancy Services Ltd | Professional & scientific | 2009 |
| 2I Commercial Services Ltd | Administrative & support | 2006 |
| 2ND Sight Limited | Administrative & support | 1997 |
| 369 Trade Ltd | Wholesale & retail | 2020 |
| A C Stone & Ceramics Limited | Manufacturing | 2018 |
| A&M Healthcare Ltd | Health & social care | 2014 |
| Abbey Contracting Services Ltd | Construction | 2025 |
| Ability Housing Association | Real estate | 1976 |
| ABZ Electrical Ltd | Construction | 2016 |
| AC Breeze Limited | Energy | 2010 |
| Acton Green Sash Windows Ltd | Construction | 2014 |
| Aesthetica Solutions Limited | Wholesale & retail | 2016 |
| African Critical Elements Ltd | Administrative & support | 2026 |
| Ageing Actively CIC | Education | 2024 |
| Airkennel Ltd | Manufacturing | 2021 |
| Airpets Limited | Other services | 1966 |
| AKS Podiatry Services Ltd | Health & social care | 2015 |
| Aldrich Trading Solutions Ltd | Information & communication | 2019 |
| Amazing Digital Solutions Ltd | Professional & scientific | 2020 |
| Amber Brasserie Limited | Hospitality | 2025 |
| Amgemini Limited | Information & communication | 2024 |
| AN Construct Ltd | Construction | 2025 |
| Angel Interiors Limited | Construction | 2017 |
| Angels Pre-School Ltd | Education | 2009 |
| Annie HOY Limited | Professional & scientific | 2011 |
| Another Lane GB Ltd | Financial services | 2014 |
| API Group UK Holdco Limited | Financial services | 2021 |
| Apple and Bears Limited | Manufacturing | 2012 |
| Apple BEE Exports Ltd | Wholesale & retail | 2004 |
| Applied Acoustic Design Holdings Limited | Professional & scientific | 2020 |
| Applied Acoustic Design Limited | Professional & scientific | 1991 |
| Aquatic Pond Life Services Limited | Other services | 2022 |
| Arrowforce Limited | Financial services | 1999 |
| ASC Couriers Limited | Transport & logistics | 2002 |
| Ashford Town (Middlesex) Football Club Limited | Hospitality | 2012 |
| Astralhub.Space Ltd | Wholesale & retail | 2025 |
| Athina Limited | Information & communication | 2020 |
| Aura Research and Technologies Limited | Information & communication | 2015 |
| Autoparts Staines Limited | Wholesale & retail | 2001 |
| Aventis Property Group Ltd | Real estate | 2025 |
| B Murphy & Co Accountants Limited | Professional & scientific | 2017 |
| Ballton Limited | Professional & scientific | 2012 |
| Bariatric & Obesity Advisors Ltd | Extraterritorial | 2024 |
| Bartenders Inc Limited | Hospitality | 2012 |
| Beauty Brow Limited | Other services | 2009 |
| Beryl Gardens Limited | Administrative & support | 2026 |
| Birmingham and Solihull Orthopaedics Limited | Health & social care | 2022 |
| Bizee Cars Ltd | Wholesale & retail | 2006 |
| Blackcode Consultancy Ltd | Professional & scientific | 2026 |
| Blackparallax Ltd | Information & communication | 2025 |
| Bloomsbury Times Limited | Arts & recreation | 1987 |
| Bonncomm Limited | Transport & logistics | 2012 |
| Bracknell DRY Cleaners Limited | Other services | 2008 |
| Brewman North Limited | Professional & scientific | 1962 |
| Broadway Pharmacy (Staines) LLP | | 2004 |
| Broadway Pharmacy Surrey Limited | Wholesale & retail | 2025 |
| Brock Enterprises Limited | Information & communication | 2022 |
| Brooks Electrical Engineering Services Ltd | Construction | 1998 |
| Bulkearth Moving Ltd | Transport & logistics | 2020 |
| Business Science Corporation Ltd | Information & communication | 2019 |
| C&C Inspection UK Ltd | Information & communication | 2024 |
| Cala Homes (Chiltern) Limited | Construction | 2014 |
| Cala Homes (Cotswolds) Limited | Construction | 1961 |
| Cala Homes (North Home Counties) Limited | Construction | 2013 |
| Cala Homes (South Home Counties) Limited | Construction | 2013 |
| Cala Homes (Southern) Limited | Professional & scientific | 1973 |
| Cala Homes (Thames) Limited | Professional & scientific | 1990 |
| Cala Homes (Yorkshire) Limited | Construction | 1988 |
| Canalside Inns Limited | Hospitality | 2017 |
| Capital Home Estate Agent Limited | Real estate | 2015 |
| Caponier Limited | Information & communication | 2009 |
| Care Collective Ltd | Health & social care | 2012 |
| Care Referral Limited | Administrative & support | 2026 |
| CARING4Y, Ltd | Health & social care | 2024 |
| Cedaforce Limited | Wholesale & retail | 2001 |
| Charlecombe Court Limited | Households | 1998 |
| Charter Place (Staines) Limited | Households | 1999 |
| Cherith Simmons Learning & Development LLP | | 2012 |
| Chosen Estate Ltd | Real estate | 2024 |
| Chrislove Healthcare Services Ltd | Health & social care | 2023 |
| Chubb Group (International) Limited | Professional & scientific | 1988 |
| Chubb Group Limited | Professional & scientific | 1957 |
| Chubb Group Properties Limited | Professional & scientific | 1987 |
| Chubb Group Security Limited | Professional & scientific | 1994 |
| Chubb International Holdings Limited | Professional & scientific | 1882 |
| Chubb Limited | Professional & scientific | 2000 |
| Chubb Security (Pensions) Limited | Financial services | 1966 |
| Church Island Bridge Company Limited | Households | 1987 |
| Cizin Limited | | 1984 |
| CJ Property Investors Limited | Real estate | 2021 |
| Clarendon Corporate Apartments Ltd | Real estate | 1987 |
| Code Convergence Limited | Information & communication | 2016 |
| Colne Valley Girls and Ladies FC Ltd | Arts & recreation | 2015 |
| Compass Plus Limited | Administrative & support | 2013 |
| Comquist Systems Limited | Information & communication | 2013 |
| Cottrell Estates and Investments Ltd | Real estate | 2025 |
| Courage and Barclay Limited | | 1959 |