| Avlution UK Limited | Information & communication | 2007 |
| Axia Capital Limited | Financial services | 2005 |
| B & J Building Consultancy Services Limited | Construction | 2005 |
| B Hall & SON Ltd | Construction | 2005 |
| Babcock Wanson UK Limited | Manufacturing | 1956 |
| Baby TOO Ltd | Professional & scientific | 2006 |
| BAF Technologies Ltd | Information & communication | 2015 |
| Balaji Dontics Limited | Health & social care | 2024 |
| Bandmodel Limited | Arts & recreation | 1992 |
| Barnes Flooring Limited | Wholesale & retail | 1955 |
| Bathroom Shop Contracts Limited | Transport & logistics | 1988 |
| Baytree Garden Contractors Limited | Other services | 1982 |
| Beck and Call Limited | Transport & logistics | 2006 |
| BEE Consulting Ltd | Construction | 2008 |
| Beechwood Park School Limited | Education | 1964 |
| Benchrealm Limited | Real estate | 1990 |
| Berkhamsted Golf Club Trustee Limited(The) | Financial services | 1923 |
| Berrington Estates Ltd | Other services | 2001 |
| Big Mama House Limited | Hospitality | 2012 |
| Billing and Howard Limited | | 1936 |
| Biokinetix Limited | Professional & scientific | 2007 |
| Birt-Tec Ltd | Information & communication | 2022 |
| Blink EYE Care Limited | Other services | 2010 |
| Blonde Sheep Events Limited | Arts & recreation | 2007 |
| Blue Chip Chauffeur Drive Cars Ltd. | Information & communication | 1993 |
| Blue Orchard Limited | Professional & scientific | 2005 |
| Bluebolt Developments Limited | Real estate | 2003 |
| Blueprint Consultants Limited | Administrative & support | 1999 |
| Blunart Properties Limited | Real estate | 1997 |
| Body Repair Centre Ltd | Wholesale & retail | 2013 |
| Booster Cushion Theatre Limited | Arts & recreation | 2003 |
| Bootifull Boot Limited | Hospitality | 2004 |
| Boshili Trading Limited | Wholesale & retail | 2024 |
| Boyd's Car Deliveries Limited | | 1976 |
| BPC Land Sales and Marketing Limited | Real estate | 2003 |
| Bradford Management Ltd | Professional & scientific | 2020 |
| Brandon & Robertson Associates Ltd | Information & communication | 2013 |
| Brandonfield Property Co. Limited | Real estate | 1972 |
| Brandstone Computers Limited | Information & communication | 1995 |
| Breitmeyer Productions Ltd | Information & communication | 2023 |
| Broadspan Securities Limited | Real estate | 1984 |
| Brookmans Park Golf Club Limited | Arts & recreation | 1933 |
| Brooks Holmes Ltd | Education | 2007 |
| Browns Engineering (GB) Limited | Manufacturing | 2006 |
| Brycedale Ltd | Real estate | 2019 |
| Bsel Hotels Ltd | Professional & scientific | 2007 |
| Building Services Management Limited | Construction | 2006 |
| Bulgarian Land and Property Limited | Real estate | 2005 |
| Burkard Manufacturing Company Limited | Manufacturing | 1959 |
| Burston Rose and Garden Centre Limited | Wholesale & retail | 1978 |
| Butterworth Estate Services Limited | Administrative & support | 2009 |
| Buypod Limited | Wholesale & retail | 2018 |
| C & R Investments Limited | Real estate | 2002 |
| C R S Decorations Limited | Construction | 2007 |
| C. B. W. Limited | Construction | 2001 |
| C.L.Tyres Limited | Manufacturing | 2019 |
| Cabs R US (UK) Limited | Wholesale & retail | 2003 |
| Caldor Trading Limited | Wholesale & retail | 1991 |
| Cambermere Limited | Professional & scientific | 1991 |
| Cambridge Steel Structures Ltd | Manufacturing | 2007 |
| Camins Ltd | Information & communication | 2025 |
| Camstage Limited | Arts & recreation | 2003 |
| Canons Field Management Limited | Administrative & support | 1988 |
| Cansoy Ltd | Professional & scientific | 2005 |
| Canton City Ltd | Hospitality | 2025 |
| Capedeal Limited | Real estate | 2001 |
| Car Boot London Ltd | Wholesale & retail | 2023 |
| Care Travel Service (Bishops Stortford) Limited | | 1972 |
| Carrier Control Systems Limited | | 1964 |
| Casa Family Ltd | Real estate | 2025 |
| Castles Estate Agents Limited | Real estate | 1986 |
| CB Appliances Limited | Wholesale & retail | 1988 |
| Cedar Close (Boreham Wood) Property Management Co Limited | Households | 1962 |
| Cedarstream Ltd | Construction | 2014 |
| Ceilspan Limited | | 1974 |
| Celsius Third Limited | Information & communication | 1967 |
| Centerland Limited | Real estate | 1991 |
| Centres of Medical Excellence and Training to the Middle East | Health & social care | 2003 |
| Century Heating & Property Maintenance Limited | | 1989 |
| Cfec Limited | Arts & recreation | 2021 |
| Challenger Consulting Limited | Information & communication | 2005 |
| Champion Elite Limited | Administrative & support | 2017 |
| Chanelle Properties Limited | Real estate | 2003 |
| Charles Bennett Limited | Professional & scientific | 2003 |
| Charlotte House School Limited | Education | 1967 |
| Chatforce Limited | | 1984 |
| Chattel Sett Limited | Professional & scientific | 2004 |
| Chenery Funeral Services Limited | Other services | 1933 |
| Cheverells House Management Company Limited | Other services | 2002 |
| CHI Kwan DO Limited | Arts & recreation | 2004 |
| Chidfit Limited | Arts & recreation | 2021 |
| Chiji Ltd | Hospitality | 2018 |
| Chisoli Treasury Solutions Ltd | Professional & scientific | 2008 |
| Chorleywood Golf Club Limited | Arts & recreation | 1975 |
| Christian James Properties Limited | Construction | 2005 |
| Christian Trampenau Limited | Professional & scientific | 2007 |
| Church Farm Agriculture Ltd | Agriculture & fishing | 2014 |
| Church Road Investments Limited | Real estate | 2006 |
| Cibo OPS. Limited | Manufacturing | 2004 |
| Cintian Ltd | Information & communication | 2019 |