| B B (Whittlesey) Limited | Real estate | 1957 |
| B B Exclusive Homes Ltd | Construction | 2015 |
| B Barnes Holdings Ltd | Financial services | 2025 |
| B C Optical Holdings Limited | Health & social care | 2025 |
| B C Optical Limited | Health & social care | 2012 |
| B C Optical Spalding Limited | Health & social care | 2025 |
| B C Wiles and SON Limited | Transport & logistics | 2004 |
| B C Wiles Limited | Transport & logistics | 2024 |
| B Chahal Transport Ltd | Transport & logistics | 2024 |
| B Ciuncanu Trans Ltd | Transport & logistics | 2021 |
| B Clarke Brickwork & Stonework Ltd | Construction | 2015 |
| B Heritage Auto Services Limited | Manufacturing | 2025 |
| B Hubbard Holdings Limited | Financial services | 2015 |
| B J Allen Transport Ltd | Transport & logistics | 2018 |
| B R Griffin Ltd | Construction | 2026 |
| B S D Engineering & Performance Limited | Professional & scientific | 2019 |
| B S D Group Holdings Limited | Financial services | 2025 |
| B S D Performance Limited | Wholesale & retail | 2025 |
| B&A Family Care Limited | Health & social care | 2025 |
| B&B HGV Services Ltd | Transport & logistics | 2018 |
| B&H Carpentry Limited | Construction | 2026 |
| B&H Hair Studio Ltd | Other services | 2025 |
| B&H Hospitality Limited | Hospitality | 2025 |
| B&S Hangars Limited | Transport & logistics | 2014 |
| B'S Autos Services and MOT Ltd | Wholesale & retail | 2025 |
| B. K. Supplies Limited | Wholesale & retail | 2006 |
| B.A.B Property Investments Ltd | Real estate | 2025 |
| B.A.Herd & SON Limited | Agriculture & fishing | 2015 |
| B.A.S Bespoke Aesthetics Limited | Other services | 2022 |
| B.Bains Properties Ltd | Real estate | 2021 |
| B.I.L.A. Construction Ltd | Construction | 2024 |
| B.R.C. (Brickwork Contractors) Limited | Construction | 2004 |
| B.S.S.B. Contract Services Limited | Construction | 1990 |
| B2B Coffee and Bar Ltd | Hospitality | 2025 |
| B2B Projects Ltd | Hospitality | 2016 |
| B2V Management Limited | Administrative & support | 2016 |
| B2V Property Investment Limited | Real estate | 2019 |
| B2V Trading Holdings Limited | Administrative & support | 2019 |
| B7 Recovery Limited | Wholesale & retail | 2018 |
| B@RRACUDA43 Limited | Health & social care | 2019 |
| BA PB Ltd | Wholesale & retail | 2025 |
| BA Training Solutions Ltd | Information & communication | 2016 |
| Baabel Group Limited | Administrative & support | 2025 |
| Baar Infotech Ltd | Information & communication | 2017 |
| Baaz Enterprises Ltd | Wholesale & retail | 2025 |
| Baba Tasty Foods Ltd | Hospitality | 2021 |
| Baba's Pizza Ltd | Hospitality | 2017 |
| Babagold Integrated Project Affairs UK Ltd | Professional & scientific | 2026 |
| Babas Pizza Fastfood Ltd | Hospitality | 2023 |
| Babu Phil Trans Ltd | Transport & logistics | 2022 |
| Baby Blue Limited | Professional & scientific | 2018 |
| Baby Dinosaur World Limited | Arts & recreation | 2022 |
| Babytobreast Limited | Health & social care | 2014 |
| Baciu M Ltd | Transport & logistics | 2023 |
| Back Properties Ltd | Real estate | 2019 |
| Background (Europe) Limited | Professional & scientific | 2018 |
| Backland Studios Ltd | Manufacturing | 2022 |
| Backseat Events Ltd | Arts & recreation | 2024 |
| Backwater Developments Ltd | Construction | 2025 |
| Backwater Fisheries Ltd | Manufacturing | 2020 |
| Bacon's College Community Services Limited | Arts & recreation | 2004 |
| Badger Accountants Limited | Information & communication | 2014 |
| Badges Limited | Manufacturing | 2007 |
| Badiork Mechanic Adonis Ltd | Wholesale & retail | 2025 |
| Badita Trans Ltd | Transport & logistics | 2025 |
| Badrhino Limited | Wholesale & retail | 2021 |
| Bagista 1972 Ltd | Transport & logistics | 2018 |
| Bahjat Ltd | Real estate | 2023 |
| Bahoo Brothers Ltd | Construction | 2022 |
| Bahoz Pizza & Kebab Ltd | Hospitality | 2025 |
| Baiamare Ltd | Hospitality | 2024 |
| Baig Brothers Limited | Hospitality | 2019 |
| Bailey Truck Solutions Limited | Extraterritorial | 2023 |
| Baileys Auto Centre Ltd | Wholesale & retail | 2025 |
| Baileys Prestige & Performance Ltd | Wholesale & retail | 2022 |
| Baileyta Ltd | Administrative & support | 2024 |
| Baja Engineering Limited | Professional & scientific | 2023 |
| Bake ME 1 Ltd | Hospitality | 2023 |
| Baker Perkins Holdings Limited | Financial services | 2015 |
| Baker Willbond Limited | Professional & scientific | 2015 |
| Bakers Lane Car Wash Ltd | Administrative & support | 2018 |
| Bakerville Ltd | Financial services | 2021 |
| Bakharla Ltd | Professional & scientific | 2024 |
| Bakhtar Grocery Store Ltd | Wholesale & retail | 2024 |
| Bako Performance and Repair Ltd | Wholesale & retail | 2026 |
| Balaam Associates Limited | Professional & scientific | 2000 |
| Balabuch Limited | Transport & logistics | 2017 |
| Balakart Limited | Real estate | 2025 |
| Balance (Oundle) Limited | Health & social care | 2022 |
| Balbella Properties Ltd | Real estate | 2013 |
| Balco Automotive Ltd | Professional & scientific | 2024 |
| Balcor Ltd | Wholesale & retail | 2025 |
| Bale's Services Limited | Construction | 2017 |
| Bales&Co Limited | Wholesale & retail | 2021 |
| Baleyarx Ltd | Health & social care | 2025 |
| Balfour Law Limited | Professional & scientific | 2007 |
| Bali Pubs Holdings Limited | Professional & scientific | 2010 |
| Balim 26 Limited | Wholesale & retail | 2026 |
| Balloon in Time Ltd | Professional & scientific | 2023 |
| Ballr Ltd | Arts & recreation | 2026 |