| Barton Contracting Services Ltd | Construction | 2023 |
| Barton Hall Close Residents Management Company Limited | Households | 2016 |
| Barton Heating and Plumbing Ltd | Construction | 2017 |
| Barton Roofing Ltd | Construction | 2026 |
| Barton Seagrave Village Hall Cafe Ltd | Hospitality | 2020 |
| Barton Telecom Services Limited | Information & communication | 2001 |
| Bartons Drove Limited | Real estate | 2012 |
| Bartram & Co (UK) Limited | Construction | 2002 |
| Barwell Aviation Limited | Transport & logistics | 2019 |
| Barwell Body Repairs Limited | Wholesale & retail | 2019 |
| Barwell Car Sales Limited | Wholesale & retail | 2026 |
| Barwest Fabrication Limited | Manufacturing | 2003 |
| Barwood Commercial Property Limited Partnership | | 2012 |
| Barwood Homes (Broadnook) Commercial Ltd | Construction | 2022 |
| Barwood Homes Broadnook Limited | Construction | 2021 |
| Barwood Property Investment Limited Partnership | | 2009 |
| Barwood Strategic Land II LLP | | 2011 |
| BAS Care Limited | Health & social care | 2023 |
| BAS Response Ltd | Construction | 2010 |
| Base Music Services Ltd | Education | 2017 |
| Baseco Limited | Administrative & support | 2007 |
| Basemark Limited | Wholesale & retail | 2012 |
| Baser Limited | Hospitality | 2008 |
| Basey Property Limited | Real estate | 2024 |
| Basha Ceramics Ltd | Construction | 2019 |
| Bashful BEE Limited | Information & communication | 2017 |
| Basia Giholt Ltd | Wholesale & retail | 2021 |
| Basic Construction Ltd | Construction | 2019 |
| Basic Outline Ltd | Wholesale & retail | 2016 |
| Basik Construction Ltd | Construction | 2022 |
| Basil Estates Ltd | Households | 2021 |
| Basingstoke East 2 Renewables Ltd | Professional & scientific | 2023 |
| Basingstoke East 7 Renewables Ltd | Professional & scientific | 2023 |
| Basoc Logistics Limited | Transport & logistics | 2025 |
| Bass Advisory Limited | Professional & scientific | 2025 |
| Bass Sal's Limited | Hospitality | 2025 |
| Bass Yumas Limited | Hospitality | 2025 |
| Bassar Holdings Limited | Administrative & support | 2010 |
| Bassaw Incorporated Ltd | Wholesale & retail | 2024 |
| BAT & Wickets Ltd | Hospitality | 2021 |
| Batchelors Building Ltd | Households | 2014 |
| Bath and Main Associates Limited | Other services | 2011 |
| Bath Road Chippy Ltd | Hospitality | 2017 |
| Bathroom Shower Panels Ltd | Wholesale & retail | 2025 |
| Bathroom Shower PVC Panels Ltd | Wholesale & retail | 2026 |
| Batista Equipment Limited | Wholesale & retail | 2025 |
| Battery Monitoring and Management Services Limited | Professional & scientific | 2013 |
| Battery Service & Components Limited | Manufacturing | 2021 |
| Battleforge Miniatures Ltd | Manufacturing | 2025 |
| Bauen Concepts Ltd | Construction | 2025 |
| Baughan Legal Limited | Professional & scientific | 2026 |
| Bauhaus Educational Services Limited | Education | 2016 |
| Bauhaus Production Limited | Information & communication | 2022 |
| Baventics Limited | Professional & scientific | 2014 |
| Bawn Construction Limited | Construction | 2016 |
| Baxter Inc Limited | Professional & scientific | 2023 |
| Bay 17 Golf Ltd | Arts & recreation | 2026 |
| Bay Island Ltd | Real estate | 2025 |
| Bayes Interiors Limited | Construction | 2019 |
| Baykurtt Limited | Hospitality | 2018 |
| Bayler Wood Properties Limited | Real estate | 2023 |
| Bayline (UK) Limited | Construction | 2012 |
| Bayliss Wright (Gados) Limited | Wholesale & retail | 1960 |
| Bayou Ltd | Wholesale & retail | 2021 |
| Bayt Rahah Ltd | Health & social care | 2025 |
| Bazan Investment Ltd | Construction | 2026 |
| Bazeley Builders Ltd | Construction | 2025 |
| Bazyli Ltd | Transport & logistics | 2020 |
| BB Afterschool Club Ltd | Health & social care | 2009 |
| BB Consultanta Ltd | Professional & scientific | 2014 |
| BB Consults Limited | Administrative & support | 2024 |
| BB Fire Alarms Ltd | Administrative & support | 2023 |
| BB Jewellery ENT Limited | Wholesale & retail | 2023 |
| BB Properties Northampton Ltd | Real estate | 2025 |
| BB Safety First Security Ltd | Other services | 2025 |
| BBF GRC Ltd | Construction | 2011 |
| Bbnn Limited | Hospitality | 2022 |
| Bbrothers Health and Logistic Limited | Health & social care | 2022 |
| BBS Drive Ltd | Administrative & support | 2020 |
| BC Workspace Limited | Construction | 2009 |
| BCA Solutions Limited | Information & communication | 2007 |
| Bcarribrooke Properties Ltd | Real estate | 2023 |
| BCC Community Land Limited | Arts & recreation | 2026 |
| BCF Action Limited | Hospitality | 1999 |
| BCG Group Limited | Financial services | 2019 |
| BCK Contracting Limited | Construction | 2005 |
| Bcoles Consulting Ltd | Professional & scientific | 2025 |
| Bcpe Diamond UK Holdco Limited | Financial services | 2017 |
| Bcph Services Ltd | Construction | 2021 |
| BCT Services 2024 Ltd | Real estate | 2024 |
| BCW Automotive Services Limited | Manufacturing | 2026 |
| BCW Holdings Ltd | Manufacturing | 2018 |
| BD Capital Limited | Professional & scientific | 2017 |
| BD Contracting Ltd | Construction | 2021 |
| BD Light Haulage Ltd | Transport & logistics | 2015 |
| BD MEM Kitchens Limited | Other services | 2019 |
| BD Taxis Ltd | Transport & logistics | 2023 |
| BDE Construct Ltd | Construction | 2025 |
| BDI Electrical Limited | Construction | 2017 |
| BDM Calu Ltd | Transport & logistics | 2020 |