| Assured Risk Solutions (ARS) Limited | Extraterritorial | 2008 |
| Astons GB Limited | Professional & scientific | 2004 |
| Astro Benefit Communication Limited | Information & communication | 2005 |
| ATA Translations Limited | Extraterritorial | 1983 |
| Atavist Ltd | Professional & scientific | 2004 |
| ATECH-2000 Limited | Information & communication | 2000 |
| Atherley Plumbing & Building Limited | Construction | 2007 |
| Atico Limited | Manufacturing | 2006 |
| Atlas Property Services Limited | Construction | 1989 |
| Attic Rooms Limited | Construction | 2003 |
| Attwell Associates Ltd | Administrative & support | 2003 |
| Auc.Art Ltd | Arts & recreation | 2016 |
| Auchter Suntime Company Limited(The) | Real estate | 1982 |
| Audentior Limited | Professional & scientific | 2007 |
| Audext Limited | Health & social care | 2014 |
| Audit Brokers Limited | Information & communication | 1988 |
| August Motors Limited | Extraterritorial | 1973 |
| Aureliot Care Recruitment Agency Ltd | Transport & logistics | 2016 |
| Aurora Solutions Ltd | Information & communication | 1997 |
| Austinbond Limited | Real estate | 1988 |
| Auto Update Limited | Information & communication | 2014 |
| Avers Enterprises Limited | Professional & scientific | 2004 |
| AVL Electrical Contractors Limited | Construction | 2007 |
| Awnet Ltd. | Information & communication | 1994 |
| Axy-Dent Ltd | Wholesale & retail | 2003 |
| Ayers Hodges Limited | Construction | 1974 |
| Ayla Restaurant & Cafe Ltd | Hospitality | 2025 |
| Azienda International Limited | Extraterritorial | 1997 |
| Azimute Limited | Professional & scientific | 2006 |
| Aztec Fire & Electrical Systems Ltd | Construction | 2005 |
| Aztec Landscapes Limited | Administrative & support | 2007 |
| B H Brickwork Limited | Construction | 2007 |
| B P Cabling Installation Limited | Construction | 2003 |
| B.B.C.H. Limited | Households | 2005 |
| B.C.S. Industrial Cleaners Limited | Arts & recreation | 1982 |
| B.J. Associates Limited | Manufacturing | 1990 |
| B.W.R. (Transport) Ltd. | Information & communication | 1989 |
| Badger Landscapes Limited | Administrative & support | 2002 |
| Bafah Limited | Professional & scientific | 2005 |
| Baikie Landscape Construction Limited | Professional & scientific | 2002 |
| Baileys Electrical Services Ltd | Construction | 2005 |
| Baileys Truck Stop (Portsmouth) Limited | Transport & logistics | 1997 |
| Bakhaty Property Limited | Administrative & support | 2004 |
| Ballard School Limited | Education | 1962 |
| Ballista Solutions Limited | Professional & scientific | 2017 |
| Balmer Lawn Garage Limited | Wholesale & retail | 2003 |
| Barc (Croft) Limited | Arts & recreation | 1992 |
| Barc (Pembrey) Limited | Arts & recreation | 1989 |
| Barker SON & Isherwood LLP | | 2007 |
| Barley House Trustee Limited | Administrative & support | 2018 |
| Barlows Butchers Limited | Wholesale & retail | 2003 |
| Barnbrook Systems Limited | Manufacturing | 1978 |
| Baros Limited | Information & communication | 2002 |
| Barrells the Funeral Directors Limited | Other services | 1964 |
| Barrie Phillipe Limited | Other services | 2003 |
| Barter Durgan Limited | Professional & scientific | 1989 |
| Barter Durgan Southern Limited | Professional & scientific | 1990 |
| Barton Garden Services Limited | Administrative & support | 2026 |
| Bartram Industries Limited | Professional & scientific | 2003 |
| Basingstoke and District Sports Trust Limited (the) | Arts & recreation | 1970 |
| Basishelp Limited | Real estate | 1992 |
| Basith Memorial Properties LLP | | 2024 |
| Basra & Basra Limited | Professional & scientific | 1996 |
| Bassetts Limited | Real estate | 2002 |
| Bayliss Ware Ltd | Professional & scientific | 1996 |
| Bayside Cabin Limited | Hospitality | 1998 |
| Bbox Limited | Manufacturing | 1989 |
| Becketts Music Limited | Wholesale & retail | 2000 |
| Bedales School | Education | 1933 |
| Bedales Services Limited | Education | 1985 |
| BEE Property Ltd | Real estate | 2005 |
| Beggarwood Estates Limited | Construction | 2003 |
| Belgarum Assembly Limited | Professional & scientific | 2007 |
| BEN Pollard Founder Advisory Limited | Professional & scientific | 2026 |
| Benfields Limited | Real estate | 2001 |
| Berks South Oxon and South Bucks Congregational Union(Incorporated)(The) | Other services | 1925 |
| Besni Limited | Hospitality | 2005 |
| Bettavend Limited | Professional & scientific | 1987 |
| Bftb Limited | Financial services | 2024 |
| Bhs-Homeimprovements.Com Ltd | Wholesale & retail | 2001 |
| Big BEE Consultants Limited | Professional & scientific | 2007 |
| Big Hammer Software Limited | Information & communication | 2004 |
| Bike IT International Holdings Limited | Professional & scientific | 2007 |
| Binary Developments Limited | Information & communication | 2005 |
| Bisqueuk Limited | Wholesale & retail | 2003 |
| Bizantec Ltd | Professional & scientific | 2003 |
| Black Cat Enterprises UK Limited | Information & communication | 1995 |
| Black Lion Express Limited | Transport & logistics | 1992 |
| Black Lion Group Limited | Professional & scientific | 1992 |
| Blackfield Hampton Ltd | Wholesale & retail | 2024 |
| Blackfield Shops Ltd | Wholesale & retail | 2026 |
| Blackhound Investments Limited | Financial services | 2015 |
| Blackledge Engineering Services Limited | Construction | 1993 |
| Blackmoor Estate Limited(The) | Agriculture & fishing | 1924 |
| Blade Window Cleaning Ltd | Administrative & support | 2002 |
| Blaydon Developments Limited | Construction | 1996 |
| Blue Angel Art Company Limited | Wholesale & retail | 2005 |
| Blue FOX Consulting Limited | Professional & scientific | 2000 |
| Blue Raptor Limited | Manufacturing | 2002 |
| Blue Ruby Enterprises Limited | Administrative & support | 2007 |