| B W Flooring Services Limited | Construction | 2012 |
| B.A.R & Sons Plumbing and Heating Ltd | Construction | 2011 |
| B.C. Groundworks Limited | Wholesale & retail | 2001 |
| B23 Marketing Limited | Administrative & support | 2015 |
| B2B Performance Ltd | Professional & scientific | 2025 |
| Baburi Group Ltd | Wholesale & retail | 2024 |
| Backyard Cuts Ltd | Other services | 2026 |
| Baelionlabs Ltd | Information & communication | 2025 |
| Baily Garner (Health & Safety) Limited | Professional & scientific | 1992 |
| Balens Insurance Finance Services Limited | Financial services | 2008 |
| Balens Limited | Financial services | 2003 |
| Balfour Property Management Limited | Real estate | 2004 |
| Ballards Property Limited | Transport & logistics | 2024 |
| Ballards Removals Holdings Limited | Administrative & support | 2014 |
| Ballards Removals Limited | Transport & logistics | 1996 |
| Banks Farms Limited | Agriculture & fishing | 2007 |
| Barclay Care Limited | Construction | 1995 |
| Barnaby Homes Limited | Construction | 2018 |
| Barnby C H Limited | Professional & scientific | 2012 |
| Barnby Properties Limited | Construction | 2018 |
| Barr Promotions and Marketing Ltd | Administrative & support | 2022 |
| Bartle Estates Limited | Real estate | 2008 |
| Bartle Transport Services Limited | Transport & logistics | 1999 |
| Barton & Co. (Farmers) Limited | Agriculture & fishing | 1984 |
| Barton Agriculture Limited | Agriculture & fishing | 2020 |
| Barton Farms Holdings Limited | Financial services | 2023 |
| Barton Solar Bumblebee Limited | Energy | 2023 |
| Barton Solar Gate Burton Limited | Energy | 2023 |
| Basa Productions Ltd | Information & communication | 2021 |
| Base Reality Ltd | Information & communication | 2022 |
| Bassetlaw Action Centre | Transport & logistics | 2004 |
| Bassetlaw Construction Services Limited | Wholesale & retail | 1989 |
| Bassetlaw Pro-Clean Ltd | Administrative & support | 2020 |
| Bassetlaw Specialist Joinery Ltd | Construction | 2026 |
| Bawtry Community Library Limited | Arts & recreation | 2013 |
| Bawtry Polo Club C.I.C. | Arts & recreation | 2018 |
| Bawtry Storage Ltd | Transport & logistics | 2020 |
| Bawtry Travel Ltd | Administrative & support | 2007 |
| BAX Plumbing & Heating Limited | Construction | 2016 |
| Baytree Bistro & Bar Ltd | Hospitality | 2024 |
| BB Catering Consulting Ltd | Wholesale & retail | 2025 |
| BB Showhouses Limited | Construction | 2006 |
| BCM Consultant Services Limited | Professional & scientific | 2022 |
| BD Transport & Travel Ltd | Transport & logistics | 2024 |
| Be-Retrosure Ltd | Transport & logistics | 2023 |
| Beachseeker LLP | | 2011 |
| Bear Paws Dog Grooming Ltd | Other services | 2024 |
| Beckett Tutoring Ltd | Education | 2020 |
| Bede Events Limited | Arts & recreation | 2003 |
| BEE Futures Ltd | Hospitality | 2021 |
| Beer Under the Clock Ltd | Hospitality | 2020 |
| Bees' Knees Corporate Limited | Professional & scientific | 2025 |
| Begum Ltd | Health & social care | 2018 |
| Being Addressed Limited | Real estate | 2025 |
| Bela Brothers Communications Ltd | Other services | 2019 |
| Belcafe Limited | Hospitality | 2019 |
| Bells Property Services Limited | Real estate | 1988 |
| BEN Gamble Electrical Ltd | Construction | 2023 |
| Benjy's Garage Ltd | Wholesale & retail | 2019 |
| Bennett's Building Contractors Limited | Construction | 2004 |
| Benoli Developments Limited | Construction | 2022 |
| Benyon’S Plumbing & Heating Limited | Construction | 2022 |
| Bergen Engines Limited | Manufacturing | 2011 |
| Bespoke Bathroom Solutions Ltd | Construction | 2022 |
| Bespoke Tiling Solutions Ltd | Construction | 2021 |
| Bestbuddies Limited | Professional & scientific | 2013 |
| Beyond Service C.I.C. | Education | 2025 |
| BIF Group Ltd | Professional & scientific | 2016 |
| Big Temp Civils Ltd | Construction | 2024 |
| Big Yellow Door Nursery Limited | Health & social care | 2020 |
| Billark Properties Limited | Real estate | 2024 |
| Billy Ford Limited | Transport & logistics | 2011 |
| Bits and Bombs Limited | Manufacturing | 2023 |
| Bizi PAY Ltd | Administrative & support | 2024 |
| Black Feather Design Limited | Wholesale & retail | 2021 |
| Blitz 1768 Ltd | Other services | 2024 |
| Bloom Broking (Number 2) Limited | Financial services | 2019 |
| Blossom Grove Management Company (Retford) Limited | Households | 2017 |
| Blue Ice Cheerleaders Ltd | Arts & recreation | 2023 |
| Blue Lemon Property Ltd | Professional & scientific | 2013 |
| Blue Moon Partnership Limited | Financial services | 2021 |
| Blue Rose Energy Services Ltd | Construction | 2019 |
| Bluebell HR Solutions Limited | Administrative & support | 2011 |
| Blyth Test Centre Ltd | Wholesale & retail | 2017 |
| BOA Construction Limited | Construction | 2017 |
| BOA Residential Limited | Real estate | 2021 |
| Bobbalec Electrical & Safety Solutions Ltd | Construction | 2024 |
| Bobby Chapman Property Limited | Real estate | 2025 |
| Bobs Buzzy Bees Limited | Manufacturing | 2024 |
| Bodymapping Limited | Professional & scientific | 2015 |
| Boiler Serv Limited | Construction | 2007 |
| Boks Invictus Ltd | Professional & scientific | 2025 |
| Bole Laser Craft Limited | Manufacturing | 2017 |
| Bolham Lane Garage Limited | Wholesale & retail | 2017 |
| Bolham Lane Management Company Ltd | Households | 2017 |
| Booth's Property Management Ltd | Real estate | 2015 |
| Born Creative Agency Limited | Professional & scientific | 2019 |
| Bover Homes Ltd | Real estate | 2026 |
| Bowness Farming Limited | Agriculture & fishing | 2010 |
| Boynton Bros. & Hallam (Ranskill) Limited | Manufacturing | 1978 |