| Atomic Marketing Services Ltd | Professional & scientific | 2022 |
| Augustino Artisan Limited | Hospitality | 2026 |
| Austenhempstead.Com Ltd | Professional & scientific | 2015 |
| Auto Adas Solutions Ltd | Wholesale & retail | 2024 |
| Automate (Louth) Limited | Wholesale & retail | 2011 |
| Autumngreen Ltd | Health & social care | 2026 |
| AW Smith (Farm Machinery) Limited | Wholesale & retail | 2004 |
| Away Days Football Ltd | Administrative & support | 2025 |
| AXES4 Ltd | Administrative & support | 2022 |
| Aylsham Growers Limited | Agriculture & fishing | 1969 |
| Aylsham Growers Services Limited | Agriculture & fishing | 1992 |
| B & T Associates Limited | Manufacturing | 1986 |
| B D Cars (Lincs) Ltd | Wholesale & retail | 2025 |
| B G Engineering Services Limited | Manufacturing | 2015 |
| B W Maintenance Limited | Administrative & support | 2002 |
| B&B Electric Solutions Ltd | Construction | 2017 |
| B&T Lighting Ltd | Manufacturing | 2013 |
| Back 2 Bear Limited | Water & waste | 2017 |
| Backburner Candles Ltd | Manufacturing | 2024 |
| Balanced Audio Systems Limited | Professional & scientific | 2006 |
| Bannister Bros. (Farms) Limited | Professional & scientific | 1974 |
| Bannister Farms Limited | Agriculture & fishing | 1962 |
| Barrow Building Services Limited | Construction | 2025 |
| Barry Patchett Ltd | Administrative & support | 2024 |
| BCB Properties Limited | Real estate | 1992 |
| Bcuk Aquatics Limited | Wholesale & retail | 2008 |
| Beacon House Solutions Ltd | Professional & scientific | 2016 |
| Beaumont's (Louth) Limited | Wholesale & retail | 2015 |
| Bedagri Ltd | Extraterritorial | 2019 |
| BEE Elsewhere Ltd | Construction | 2025 |
| Beechey Court Management Company (Lincs) Ltd | Real estate | 2022 |
| Beeswax Farming Ltd | Agriculture & fishing | 2021 |
| Bellas Dog Grooming Services Limited | Other services | 2022 |
| Bellflower and Bloom CIC | Education | 2025 |
| BEN Ashton and SON Limited | Water & waste | 2008 |
| BEN Stubbs Next Generation Investments Ltd | Financial services | 2024 |
| BEN Tasker Flooring and Interiors Ltd. | Construction | 2002 |
| Benrick Holdings Limited | Financial services | 2013 |
| Bentleys Homes Ltd | Construction | 2019 |
| Bentleys Letting Limited | Real estate | 2023 |
| Best Interest Consultancy Limited | Health & social care | 2014 |
| BET Noble Ltd | Arts & recreation | 2026 |
| Bett Holdings Limited | Real estate | 2021 |
| Betties Limited | Hospitality | 2025 |
| BFB Group Ltd | Professional & scientific | 2025 |
| Billyfulfilly Ltd | Wholesale & retail | 2025 |
| Bilney House Developments Ltd | Construction | 2024 |
| Bilney House Ltd | Financial services | 2024 |
| Bingolaris Ltd | Hospitality | 2026 |
| Biochain IP Holdings Limited | Financial services | 2025 |
| Biochain Limited | Professional & scientific | 2025 |
| Bird Food Recipes Limited | Administrative & support | 2004 |
| Bishopthorpe Farm Landholdings Limited | Real estate | 2015 |
| Black Cat Security Ltd | Administrative & support | 2023 |
| Blanchard Enterprises Ltd | Hospitality | 2017 |
| Blaze Competitions Ltd | Wholesale & retail | 2022 |
| Blockfree Services Limited | Water & waste | 2002 |
| Blockfree Waste Services Limited | Real estate | 2005 |
| Blue Bell Court (Barton) Management Company Limited | Real estate | 2015 |
| Blueprint Document Solutions Limited | Manufacturing | 2010 |
| Bluworx Limited | Information & communication | 2014 |
| BOB Malloney Associates Limited | Professional & scientific | 2002 |
| Bodrum A.S Limited | Hospitality | 2018 |
| Bonnies Health Limited | Manufacturing | 2024 |
| Boylan Distribution Ltd | Transport & logistics | 2008 |
| Brackenborough Lakes Ltd | Hospitality | 2023 |
| Brackenborough Limited | Hospitality | 2002 |
| Brackenborough Newsagents Limited | Wholesale & retail | 2003 |
| Brain First Community Ltd | Information & communication | 2024 |
| Bricktasticuk Ltd | Wholesale & retail | 2024 |
| Brickyard Fishery Ltd | Hospitality | 2026 |
| Brink Media Ltd | Information & communication | 2017 |
| British Apples and Pears Limited | Agriculture & fishing | 1990 |
| British Berry Growers Limited | Administrative & support | 1996 |
| British Herbs Association Limited | Agriculture & fishing | 2025 |
| British Peas and Beans Association Limited | Agriculture & fishing | 2025 |
| British Stone Fruits Limited | Administrative & support | 2020 |
| Brocklebank Reclaims Limited | Wholesale & retail | 2015 |
| Brockwell & Brockwell Ltd | Information & communication | 2017 |
| Bromley's Vehicle Servicing & Repairs Ltd | Wholesale & retail | 2011 |
| Brotherhood-Uk Ltd | Other services | 2023 |
| Brownies Bike Spares Limited | Wholesale & retail | 2016 |
| Bruce & Norman Associates Limited | Professional & scientific | 2020 |
| Bruxco Limited | Real estate | 1998 |
| Buckets Animal Feeds Ltd | Wholesale & retail | 2017 |
| Bulldog CSU Ltd | Manufacturing | 2023 |
| Burbridge Packaging (Louth) Limited | Manufacturing | 2009 |
| Burkshire Property Ltd | Financial services | 2022 |
| Burnett Global Education Limited | Education | 2016 |
| Business Asset Finance Limited | Financial services | 2018 |
| Buster's Cafe and Takeaway Limited | Hospitality | 2024 |
| Buyerpower Ltd | Professional & scientific | 2012 |
| BW Baby Limited | Wholesale & retail | 2022 |
| C & L Fairburn Holdings Limited | Financial services | 2025 |
| C & L Fairburn Property Developments Ltd | Construction | 2009 |
| C & S Howard Ltd | Wholesale & retail | 2024 |
| C and S Goodear Services Ltd | Professional & scientific | 2006 |
| C M Performance Engineering Limited | Wholesale & retail | 2011 |
| C S H Consultancy Ltd. | Real estate | 2000 |
| C&J Daniels Properties Limited | Real estate | 2021 |