| Banol Ltd | Transport & logistics | 2016 |
| Bantony Estates Limited | Real estate | 2024 |
| Banu Transport Ltd | Transport & logistics | 2018 |
| Bapon IT Academy Ltd | Education | 2024 |
| Bapon IT Services Ltd | Information & communication | 2023 |
| Baqi Tours Limited | Administrative & support | 2024 |
| Bar Cafe Milano Ltd | Hospitality | 2019 |
| Bar&Rem Ltd | Wholesale & retail | 2016 |
| Barafundle Bay Software Ltd | Information & communication | 2025 |
| Baraka Appliances Ltd | Other services | 2026 |
| Baraka E Limited | Other services | 2026 |
| Baraka Gourmet Ltd | Hospitality | 2025 |
| Barakah Asset Holdings Limited | Financial services | 2025 |
| Barakah HCS Ltd | Health & social care | 2024 |
| Barakah Healthcare Limited | Health & social care | 2013 |
| Barakah Hijama Clinic Limited | Health & social care | 2026 |
| Barakah Petersfield Garden Ltd | Real estate | 2026 |
| Barakah Property Holding Group Ltd | Construction | 2026 |
| Barbara-Fran | | 2003 |
| Barbarossa Brickwork Ltd | Construction | 2026 |
| Barber & Sun Limited | Other services | 2007 |
| Barber Box (Towcester) Ltd | Other services | 2023 |
| Barber V Holdings Ltd | Financial services | 2026 |
| Barber V Properties Ltd | Real estate | 2026 |
| Barbican Construction Limited | Construction | 2003 |
| Barbour Welting (U.K.) Limited | Wholesale & retail | 1997 |
| Barby Pomarium Ltd | Agriculture & fishing | 2024 |
| Barby Sporting Limited | Hospitality | 2002 |
| Barclaygrant Properties Ltd | Real estate | 2021 |
| Bardeli Express Ltd | Administrative & support | 2026 |
| Bare Beauty Aesthetics Ltd | Other services | 2017 |
| Bare Enterprise Limited | Professional & scientific | 2015 |
| Bare Skin and Body Co Ltd | Education | 2024 |
| Bare Skin Inc Ltd | Education | 2021 |
| Barefooted Arts CIC | Arts & recreation | 2026 |
| Barfield Estate Planning Limited | Other services | 2021 |
| Barfield Estates Northampton Ltd | Real estate | 2024 |
| Barfield Estates Pines Limited | Real estate | 2025 |
| Barfield Financial Advisors Limited | Financial services | 1995 |
| Barfield Wealth Limited | Financial services | 2017 |
| Barford Electrical Limited | Construction | 2022 |
| Barford Woodlands Limited | Real estate | 2003 |
| Barfordandson Ltd | Real estate | 2020 |
| Bargain Grass Limited | Professional & scientific | 2016 |
| Bargains 2 Go Outlet Ltd | Wholesale & retail | 2026 |
| Bargains 2B Found Limited | Wholesale & retail | 2021 |
| Bargainsluxuryhometreats Ltd | Wholesale & retail | 2024 |
| Bargrave Developments Limited | Construction | 2006 |
| Bari & Honufa Holdings Limited | Hospitality | 2023 |
| Bari & Sons Investments Limited | Construction | 2016 |
| Barian Technology Limited | Administrative & support | 2003 |
| Barking Bags Ltd | Manufacturing | 2018 |
| Barking Developments Company Limited | Wholesale & retail | 1935 |
| Barkli Ltd | Construction | 2022 |
| Barkston Estates Ltd | Real estate | 2022 |
| Barley & Vine Group Ltd | Hospitality | 2026 |
| Barley and Vine Events Ltd | Hospitality | 2026 |
| Barlow Doherty Marketing, Design and Advertising Limited | Professional & scientific | 1997 |
| Barn 2 Projects Ltd | Professional & scientific | 2021 |
| Barn 4 Ltd | Agriculture & fishing | 2020 |
| Barn OWL Traders Ltd | Wholesale & retail | 2024 |
| Barnaville Plastering Limited | Extraterritorial | 2014 |
| Barndoor Consulting Ltd | Professional & scientific | 2015 |
| Barnes & Co Northampton Ltd | Real estate | 2025 |
| Barnes Brick Cutting Services Ltd | Construction | 2024 |
| Barnes Building Services Ltd | Construction | 2015 |
| Barnes Lawrence Limited | Financial services | 2021 |
| Barnes Property & Development Ltd | Real estate | 2018 |
| Barnes Scaffolding Services Ltd | Construction | 2020 |
| Barnes-Charles Property Ltd | Real estate | 2022 |
| Barnes-West Developments Ltd | Construction | 2019 |
| Barnett Landscapes Ltd. | Administrative & support | 2007 |
| Barnfield Top Farm Ltd | Agriculture & fishing | 2021 |
| Barngate Developments Limited | Water & waste | 2013 |
| Barnmore Management Services Limited | Administrative & support | 2016 |
| Baron Court (Northampton) RTM Company Limited | Households | 2012 |
| Baron Group NBB Ltd | Professional & scientific | 2012 |
| Baron Motors Limited | Manufacturing | 1959 |
| Baron Sons (Holdings) Limited | Professional & scientific | 1991 |
| Barosh LLP | | 2017 |
| Barratts Leisure Limited | Real estate | 1990 |
| Barreto Golf Ltd | Wholesale & retail | 2021 |
| Barrett Homes Limited | Real estate | 2024 |
| Barrington Bramley Limited | Arts & recreation | 2002 |
| Barrington Stud Ltd | Construction | 2020 |
| Barros Transport Ltd | Transport & logistics | 2022 |
| Barry Car Engineering Ltd | Wholesale & retail | 2021 |
| Barry Halliday Legal Services Ltd | Professional & scientific | 2025 |
| Barry Howard Group Ltd | Construction | 2019 |
| Barry Howard Homes (Hstone) Ltd | Construction | 2020 |
| Barry Howard LLP | | 2004 |
| Barry Johnson Financial Services Limited | Financial services | 2015 |
| Bartek HGV Ltd | Construction | 2019 |
| Bartella Property Holdings Limited | Real estate | 2024 |
| Bartella's Coffee House Limited | Hospitality | 2017 |
| Bartholomew Farm LLP | | 2022 |
| Bartholomew Isaacs Limited | Construction | 2019 |
| Bartlomiej Kowalczyk Limited | Transport & logistics | 2016 |
| Barton Broadband Ltd | Information & communication | 2015 |
| Barton Coles Accounting Limited | Professional & scientific | 2018 |