| Blue Mountain Capacity Limited | Financial services | 2020 |
| Bluefriars Acquisition Services Limited | Professional & scientific | 2018 |
| Bluefriars Brokers Limited | Financial services | 2013 |
| Bluefriars Group Limited | Financial services | 2013 |
| Bluefriars Training and Consultancy Limited | Financial services | 2016 |
| Bluetek Designs Limited | Construction | 2014 |
| Blumkin Limited | Professional & scientific | 2025 |
| BMR Composites Limited | Manufacturing | 2019 |
| BMR Karting Limited | Arts & recreation | 2016 |
| BMR Motorcycles Limited | Wholesale & retail | 2016 |
| BMR Racing Limited | Arts & recreation | 2014 |
| BON BON Admin Ltd | Administrative & support | 2024 |
| Bouncing Ball Limited | Information & communication | 2009 |
| Bowford Investments Limited | Real estate | 2007 |
| BPM Engineering Supplies Limited | Wholesale & retail | 2025 |
| BPR Consulting Ltd | Administrative & support | 2011 |
| Brent Pelham Cross Country Limited | Arts & recreation | 2023 |
| Brevent Services Limited | Professional & scientific | 2006 |
| Bright Barn Training Limited | Professional & scientific | 2020 |
| Brooks Plumbing and Heating Limited | Construction | 2018 |
| Brookson (5279E) Limited | Administrative & support | 2007 |
| Buntingford and Royston Football Coaching Ltd | Education | 2025 |
| Buntingford Construction Services Limited | Construction | 2020 |
| Buntingford EA Limited | Real estate | 2018 |
| Buntingford Film Consulting Services Limited | Information & communication | 2025 |
| Buntingford Fish & Chips Ltd | Hospitality | 2025 |
| Buntingford Laser Clinic Ltd | Other services | 2025 |
| Buntingford Leisure Group Limited | Hospitality | 2022 |
| Buntingford Nails Limited | Other services | 2022 |
| Buntingford School of Dance Limited | Education | 2012 |
| Buntingford Sports Club Ltd | Hospitality | 2003 |
| Buntingford Taxis Limited | Transport & logistics | 2024 |
| Buntingford Town Football Club Limited | Arts & recreation | 2025 |
| Burnt OUT Retreats Ltd | Other services | 2025 |
| Butt Sniffers Boutique Dog Hotel Ltd | Agriculture & fishing | 2023 |
| Buttermilk Properties Ltd | Construction | 2018 |
| C E Harris Transport Ltd | Transport & logistics | 2024 |
| C K General Builders Limited | Construction | 2013 |
| C&Y Scaffolding Ltd | Construction | 2024 |
| C2S Recovery Limited | Wholesale & retail | 2023 |
| CA Electrical & Lighting Ltd. | Construction | 2015 |
| Caldeira Consulting Company Ltd | Professional & scientific | 2023 |
| Calloway Supplies Limited | Wholesale & retail | 2025 |
| Carbis Design Limited | Professional & scientific | 2008 |
| Carbon & Tyde Ltd | Manufacturing | 2018 |
| Carbon NET Zero Ltd | Professional & scientific | 2022 |
| Carrotcake Limited | Arts & recreation | 2006 |
| Cartwright Curtis Limited | Real estate | 2025 |
| Cavendish Plumbing Heating and GAS Ltd | Construction | 2022 |
| CEH Property Holdings Ltd | Real estate | 2024 |
| Cemm Communications Ltd | Wholesale & retail | 2018 |
| Chandu Toolmakers & Mouldings Limited | Administrative & support | 2001 |
| Chapel END Innovation Ltd | Manufacturing | 2019 |
| Chaplin Construction Services Ltd | Construction | 2025 |
| Charlie's Farm Ltd | Transport & logistics | 2025 |
| Chateau Property Ltd | Real estate | 2023 |
| Cherie LEE Interiors Limited | Professional & scientific | 2015 |
| Cherry Green Construction Limited | Construction | 2025 |
| Chevis Limited | Professional & scientific | 2006 |
| Chloe Lamb Fine Art Limited | Professional & scientific | 2012 |
| Chris Dellar Limited | Real estate | 2004 |
| Chris Kirby Consulting Ltd | Education | 2012 |
| Church Lane Creative Ltd | Professional & scientific | 2020 |
| CLS Roofing Specialists Limited | Construction | 2015 |
| CMM Plumbing and Heating Ltd | Construction | 2024 |
| Coach IT Forward Ltd | Professional & scientific | 2021 |
| CODE8 Ltd | Information & communication | 2024 |
| Codicote Quarry Limited | Mining & quarrying | 1993 |
| Commontimerecords Limited | Information & communication | 2025 |
| Complete Refurbs Ltd | Construction | 2014 |
| Condover House Management Company Limited | Households | 2009 |
| Conifers Construction Limited | Financial services | 2025 |
| Contract Interior Solutions Limited | Construction | 2017 |
| Corbiere Renewables Limited | Manufacturing | 2013 |
| Corecruit Limited | Administrative & support | 2021 |
| Country Maids Limited | Administrative & support | 2006 |
| Cozeepod Ltd | Administrative & support | 2023 |
| Craftedge 3D Ltd | Manufacturing | 2026 |
| Crane School of Reflexology Limited | Professional & scientific | 1995 |
| Cranville Builders Limited | Construction | 2017 |
| Creative Carpets and Flooring Ltd | Construction | 2020 |
| Crossfit Buntingford Ltd | Arts & recreation | 2019 |
| Crowngate Construction Ltd | Construction | 2026 |
| CSB Automotive Ltd | Wholesale & retail | 2015 |
| Cure & Simple Ltd | Manufacturing | 2014 |
| CW Electrical (Herts) Ltd | Construction | 2011 |
| Cybertools Limited | Manufacturing | 2005 |
| D a Rowley Limited | Construction | 1997 |
| D and a Fitness Ltd | Arts & recreation | 2025 |
| D E G Simpson & Sons Limited | Water & waste | 2016 |
| D. Bishop Limited | Hospitality | 1937 |
| Dalp Engineering Limited | Construction | 2009 |
| Dandav Services Ltd | Education | 2023 |
| Dane Business Consulting Ltd | Professional & scientific | 2021 |
| Datalec Power Installations Limited | Manufacturing | 2012 |
| Datalec Precision Installations - Aisle Containment & Caging Solutions Limited | Manufacturing | 2019 |
| Dayz OFF Decorating Ltd | Construction | 2021 |
| Dayz OFF Maintenance Ltd | Construction | 2025 |
| DDK Global Care Ltd | Health & social care | 2023 |
| DDM Holdings Limited | Financial services | 2016 |