| Business Energy for Less Ltd | Energy | 2014 |
| Business Interactive Limited | Professional & scientific | 2001 |
| Business Money Promotions Ltd | Professional & scientific | 2004 |
| Business Waste Management Limited | Manufacturing | 2012 |
| BUSINESSF1 Magazine Ltd | Information & communication | 2020 |
| Butcher Brothers Limited | Wholesale & retail | 2018 |
| Butler Bricklayers Limited | Construction | 2016 |
| Butt Trading Ltd | Transport & logistics | 2004 |
| Butt's Sweets & Curries Ltd | Wholesale & retail | 2007 |
| Buttar Haulage Ltd | Transport & logistics | 2025 |
| Butterfly Screen Print and Packing Solutions Limited | Wholesale & retail | 2019 |
| Butterley Brick Limited | Extraterritorial | 2016 |
| Butterwick Bakes Limited | Manufacturing | 2017 |
| Butterworth Heating Limited | Construction | 2009 |
| Buttons Day Nursery School Limited | Education | 2004 |
| BUY2INVEST Ltd | Real estate | 2025 |
| Buykia Ltd | Wholesale & retail | 2025 |
| Buystation Ltd | Wholesale & retail | 2025 |
| Buzbees Beverages Limited | Wholesale & retail | 2018 |
| Buzbees Drinks USA Limited | Wholesale & retail | 2019 |
| Buzz Trans Ltd | Transport & logistics | 2018 |
| Buzzard Building Company Ltd | Construction | 2021 |
| Buzzard Meadows (Leighton Buzzard) Residents Management Company Limited | Households | 2018 |
| BV Tech Ltd | Other services | 2015 |
| BV Tiling Ltd | Manufacturing | 2022 |
| BVM Glocal Ltd | Wholesale & retail | 2020 |
| BVN Brickwork Ltd | Construction | 2018 |
| Bvtv International Limited | Information & communication | 1997 |
| BW Home Developments Ltd | Construction | 2023 |
| BW Trading Group Ltd | Wholesale & retail | 2023 |
| BW3 Electrical Ltd | Construction | 2024 |
| BWS Electrical Services Ltd | Construction | 2024 |
| BXB Developments Limited | Construction | 2017 |
| BXG Logistics Ltd | Transport & logistics | 2024 |
| BXM Property Limited | Real estate | 2025 |
| BY Claire Ltd | Wholesale & retail | 2021 |
| BY Millimetres Ltd | Construction | 2021 |
| BY Steph Ltd | Public administration | 2026 |
| Byers Consultancy Ltd | Hospitality | 2025 |
| Byfield Retail Limited | Wholesale & retail | 2007 |
| Byju Trans Ltd | Transport & logistics | 2022 |
| Byrne Formwork Limited | Construction | 2007 |
| Byron & Partners Ltd | Construction | 2023 |
| Byron Real Estate Limited | Construction | 2022 |
| Bysil Ltd | Wholesale & retail | 2025 |
| Bystander Magazines Limited | Information & communication | 2013 |
| BYTEBARGAINS66 Ltd | Wholesale & retail | 2025 |
| Byteforge Technologies Ltd | Information & communication | 2026 |
| Bytevault Limited | Wholesale & retail | 2024 |
| Byworth Waste Removal Services Ltd | Water & waste | 2024 |
| C C Diliu Ltd | Transport & logistics | 2019 |
| C & C Enterprises Northampton Limited | Real estate | 2021 |
| C & C Home Improvements Limited | Construction | 2007 |
| C & C Machine Services Ltd | Manufacturing | 2017 |
| C & E Enterprises UK Limited | Professional & scientific | 2005 |
| C & E S Limited | Information & communication | 2002 |
| C & K Services (UK) Limited | Other services | 2005 |
| C & L Ltd | Real estate | 2025 |
| C & M Rutland Financial & Courier Services Limited | Transport & logistics | 2006 |
| C & N Building Services Limited | Administrative & support | 2010 |
| C & P Property Estates Ltd | Real estate | 2013 |
| C & RN Ltd | Professional & scientific | 2023 |
| C & S Eyre Consulting Limited | Professional & scientific | 2025 |
| C & S Taxis (London) Limited | Transport & logistics | 2005 |
| C & Z Equity Ltd | Financial services | 2022 |
| C & Z Property Ltd | Real estate | 2022 |
| C a Components Ltd. | Financial services | 2002 |
| C a Mclellan Limited | Construction | 2009 |
| C and F Holdco Ltd | Financial services | 2024 |
| C and F Property Ltd | Real estate | 2016 |
| C B Motorsport Limited | Professional & scientific | 2014 |
| C B Skinner Construction Ltd | Construction | 2019 |
| C Butt Enterprises Limited | Financial services | 2023 |
| C Butt Holdings Limited | Professional & scientific | 2008 |
| C Butt Properties Limited | Real estate | 2023 |
| C D Blinds Ltd | Construction | 2015 |
| C D Properties Lettings Ltd | Real estate | 2022 |
| C G Developments (UK) Ltd | Real estate | 2006 |
| C G Trading Limited | Construction | 2015 |
| C Guest Co Ltd | Information & communication | 2021 |
| C H R S Limited | Professional & scientific | 2006 |
| C H Specialist Training Ltd | Water & waste | 2018 |
| C Holdings Limited | Financial services | 2023 |
| C J Ground Works & Civil Engineering Limited | Construction | 2003 |
| C J Haulage Limited | Transport & logistics | 2023 |
| C J Howell Enterprises Ltd | Real estate | 2020 |
| C J M Building Services Ltd | Administrative & support | 2021 |
| C J Parts Limited | Wholesale & retail | 2006 |
| C J R (Midlands) Limited | Construction | 2000 |
| C J Reed Engineering Ltd | Manufacturing | 2018 |
| C Liddle Consultancy Ltd | Arts & recreation | 2022 |
| C Logistics Solutions Limited | Professional & scientific | 2013 |
| C M I Consultant Limited | Manufacturing | 2012 |
| C N Plastics Limited | Real estate | 2004 |
| C Nash Brickwork Ltd | Construction | 2026 |
| C Polar Filters UK Limited | Wholesale & retail | 2024 |
| C Projects Limited | Professional & scientific | 2010 |
| C Roman Construction Ltd | Construction | 2024 |
| C S Plumbing and Heating Limited | Construction | 2011 |
| C Thomason Limited | Construction | 2006 |