| Biff Trading Limited | Information & communication | 2008 |
| Bifrangi UK Limited | Manufacturing | 2001 |
| Big Bump Ltd | Financial services | 2026 |
| Big Buzzby Trucking Ltd | Transport & logistics | 2022 |
| Big Couriers Ltd | Transport & logistics | 2017 |
| Bigears Property Limited | Real estate | 2016 |
| Bight Moat Properties Ltd | Real estate | 2019 |
| Bignomics Ltd | Wholesale & retail | 2024 |
| Billericay Properties Limited | Real estate | 2018 |
| Billinghay Forge Limited | Manufacturing | 2003 |
| Billinghay Garage Ltd | Wholesale & retail | 2023 |
| Billinghay Hand Car Wash Ltd | Administrative & support | 2025 |
| Billinghay Sawmill Ltd | Manufacturing | 2026 |
| Billinghay Stags FC CIC | Education | 2023 |
| Billveron Limited | Hospitality | 2017 |
| BIN Busters Waste Removals Ltd | Water & waste | 2025 |
| Bingham & Young Staff Ltd | Professional & scientific | 2024 |
| Bingham-Smith Property Services Ltd | Households | 2022 |
| BIO Baits Ltd | Wholesale & retail | 2020 |
| BIO Carbonics Limited | Agriculture & fishing | 2018 |
| Bio-Dynamics Tanks Ltd | Construction | 2021 |
| Biochef Spares UK Ltd | Manufacturing | 2026 |
| Biocrest Ltd | Water & waste | 2014 |
| Biodiversity Futures Initiative Ltd | Professional & scientific | 2023 |
| Biomatics Limited | Professional & scientific | 2021 |
| Biota Ltd | Professional & scientific | 2020 |
| Birch Street Coffee Ltd | Hospitality | 2026 |
| Birchmount Solutions Ltd | Financial services | 2017 |
| Birchwood Boiler House Community Hall Ltd | Hospitality | 2026 |
| Birchwood Buzz Limited | Information & communication | 2013 |
| Birchwood Grange Management Company Limited | Other services | 1990 |
| Birchwood Legal Ltd | Professional & scientific | 2024 |
| Birchwood Nails Ltd | Other services | 2026 |
| Bird Feed Direct Ltd | Wholesale & retail | 2023 |
| Bird's Carpentry Ltd | Construction | 2017 |
| Birdbrook Property Limited | Real estate | 1993 |
| Birdbrook Rosettes Limited | Manufacturing | 2011 |
| Birkdale Investments Ltd | Real estate | 2014 |
| Bisel Limited | Agriculture & fishing | 2005 |
| Bison Projects Ltd | Construction | 2021 |
| Bistro Polonia Ltd | Hospitality | 2015 |
| Bites Lincoln Ltd | Hospitality | 2024 |
| Biuro Pomocy Ltd | Other services | 2026 |
| Bizarden Limited | Professional & scientific | 2022 |
| Bizarden Research Limited | Administrative & support | 2025 |
| Bizz PA Ltd | Administrative & support | 2025 |
| BJ Hayes Ltd | Financial services | 2018 |
| BJC Construction Limited | Agriculture & fishing | 2019 |
| BK International Business Management (BK IBM) Ltd | Professional & scientific | 2023 |
| BKB Commercials Ltd | Wholesale & retail | 2017 |
| Black Barn Engineering Ltd | Professional & scientific | 2023 |
| Black Business Lincolnshire CIC | Other services | 2025 |
| Black Cat Cabs Ltd | Transport & logistics | 2013 |
| Black Cat Travel Ltd | Transport & logistics | 2009 |
| Black J a Limited | Financial services | 2023 |
| Black Peppermint Events Ltd | Hospitality | 2024 |
| Black Series Professional Detailing Ltd | Other services | 2019 |
| Black Swan Coningsby Ltd | Hospitality | 2016 |
| Black Triangle Ltd | Transport & logistics | 2012 |
| Blackbody Limited | Arts & recreation | 2009 |
| Blackbow Creative Ltd | Arts & recreation | 2018 |
| Blackstone Groundworks & Surfacing Ltd | Construction | 2025 |
| Blackwhite Gallery Limited | Wholesale & retail | 2022 |
| Blades Advertising & Marketing Ltd. | Professional & scientific | 1995 |
| Blair Music Production Ltd | Information & communication | 2015 |
| Blake and Co Ltd | Professional & scientific | 2013 |
| Blake Chapman Ltd | Real estate | 2025 |
| Blake Edwards Plumbing & Heating Limited | Construction | 2002 |
| Blanchard-Butter Property Limited | Real estate | 2022 |
| Blankney Estates Limited | Agriculture & fishing | 1940 |
| Blankney Golf Club Limited | Arts & recreation | 2024 |
| Blast Cleaning UK Ltd | Manufacturing | 2021 |
| Blaze Driver Hire Ltd | Transport & logistics | 2026 |
| Blaze Solar Ltd | Construction | 2022 |
| Blazeline Welding and Pipefitting Solutions Ltd | Manufacturing | 2026 |
| Bleiker & Williams Ltd | Health & social care | 2011 |
| Blend Branston Ltd | Hospitality | 2026 |
| Blenheim Road (Lincoln) Management Company Limited | Households | 2014 |
| Blenheim Square Management Company Limited | Administrative & support | 2006 |
| Blessed Global Limited | Health & social care | 2025 |
| Blesta Club Ltd | Information & communication | 2023 |
| BLH Paving Solutions Ltd | Construction | 2017 |
| Bliasaka Ltd | Transport & logistics | 2021 |
| Blinkclean Services Limited | Real estate | 2026 |
| Blnk.Barbers Ltd | Other services | 2024 |
| Blonde LOX Ltd | Information & communication | 2024 |
| Bloom Demolition & Crushing Ltd | Administrative & support | 2014 |
| Bloom Demolition and Excavation Limited | Construction | 2009 |
| Bloom Digital Media Ltd | Professional & scientific | 2024 |
| Bloom Juice Ltd | Wholesale & retail | 2024 |
| Bloom Lincoln Ltd | Other services | 2022 |
| Bloom Waters Properties Limited | Real estate | 2026 |
| Blubutton Digital Ltd | Information & communication | 2022 |
| Blue Bear Solutions Limited | Professional & scientific | 2025 |
| Blue Blanket Retail Solutions Ltd | Information & communication | 2018 |
| Blue Chip Property Group Ltd | Construction | 2020 |
| Blue Cloud Shisha Ltd | Hospitality | 2025 |
| Blue Double U Ltd | Wholesale & retail | 1997 |
| Blue Flame Installations Limited | Construction | 2013 |
| Blue Gold Properties Ltd | Construction | 2021 |