| Barbiry Ltd | Public administration | 2023 |
| Barbour Solutions Limited | Information & communication | 2010 |
| Barck Ltd | Real estate | 2019 |
| Bargain Beers Store Ltd | Wholesale & retail | 2025 |
| Bargyloo Farm Management Company Limited | Real estate | 2019 |
| Bariatric Surgery Limited | Financial services | 2013 |
| Bark Avenue Grooming Ltd | Agriculture & fishing | 2023 |
| Bark Cottage Limited | Other services | 2026 |
| Barker Civil Engineering Limited | Professional & scientific | 2019 |
| Barker Labels Ltd | Manufacturing | 2011 |
| Barker Properties North West Limited | Real estate | 2015 |
| Barker Talent Solutions Limited | Administrative & support | 2025 |
| Barkinmouse Ltd | Wholesale & retail | 2019 |
| Barlow Search Limited | Administrative & support | 2011 |
| BARNARD33 Talent Ltd | Administrative & support | 2024 |
| Barnett's Safety Equipment Service Limited | Wholesale & retail | 1995 |
| Barney Digital Ltd | Professional & scientific | 2021 |
| Barnfield IT Services Limited | Information & communication | 2017 |
| Barns Physiotherapy Limited | Other services | 2026 |
| Barondale Estates Ltd | Hospitality | 2024 |
| Barradon Limited | Professional & scientific | 2018 |
| Barrel Bar Ltd | Hospitality | 2022 |
| Barrence Seedorf Ltd | Arts & recreation | 2025 |
| Barrett Design Services Limited | Professional & scientific | 2023 |
| Barrford Property (NW) Limited | Real estate | 2024 |
| Barrington Dolby Limited | Information & communication | 2014 |
| Barrington Hulse Tax & Advisory Limited | Professional & scientific | 2021 |
| Barrington Leisure Limited | Hospitality | 2020 |
| Barrington Properties Ltd | Real estate | 2017 |
| Barrington South Limited | Real estate | 2026 |
| Barriskell Consulting Ltd | Information & communication | 2019 |
| Barrow Electrical Ltd | Construction | 2011 |
| Barrowland Freight Services Limited | Transport & logistics | 2025 |
| Barry Tildsley Sales and Management Training Limited | Administrative & support | 2025 |
| Bars 2 YOU Limited | Hospitality | 2008 |
| Bars and Beyond Limited | Hospitality | 2024 |
| Bars Partitions & Ceiling Ltd | Construction | 2023 |
| Bart Transport Limited | Transport & logistics | 2025 |
| Bartlett Capital Management LP | | 2013 |
| Barton Air Limited | Arts & recreation | 1991 |
| Barton Civil Engineers Limited | Construction | 2005 |
| Barton PA Limited | Real estate | 2023 |
| Barton Willmore Design Limited | Professional & scientific | 1987 |
| Barton Willmore Holdings Limited | Administrative & support | 1987 |
| Bartone Transport Ltd | Transport & logistics | 2019 |
| BAS (NW) Limited | Wholesale & retail | 2013 |
| Base Consulting Ltd | Professional & scientific | 2025 |
| Base Hair Academy Limited | Other services | 2018 |
| Base Industries Limited | Extraterritorial | 2018 |
| Base Resolve Ltd | Information & communication | 2016 |
| Basesixty Ltd | Professional & scientific | 2021 |
| Basildon Power Limited | Energy | 2014 |
| Basma Consultancy Limited | Administrative & support | 2014 |
| Bass Automotive Limited | Professional & scientific | 2017 |
| Bass Orthodontics Limited | Health & social care | 2009 |
| Bate Transport Solutions Ltd | Transport & logistics | 2022 |
| Bates & Hunt Limited | Extraterritorial | 2007 |
| Bates Farm Events Limited | Agriculture & fishing | 2023 |
| Bates Test Services Ltd | Other services | 2019 |
| Bath Time Solutions Ltd | Wholesale & retail | 2025 |
| Bather Properties Limited | Real estate | 2021 |
| Bathroom Angels Limited | Professional & scientific | 2023 |
| Batida RIO C.I.C. | Arts & recreation | 2020 |
| Baton Systems Limited | Information & communication | 2019 |
| Batrak Holdings Ltd | Financial services | 2024 |
| Battersby CAD Services Ltd | Administrative & support | 2021 |
| Bay Area Capital Limited | Other services | 2020 |
| Bay Controls Ltd | Professional & scientific | 2018 |
| Bay Research Services Ltd | Other services | 2019 |
| Bay Road Consulting Limited | Administrative & support | 2024 |
| Bay Tree Finance Ltd | Financial services | 2024 |
| Bayford OIL Limited | Extraterritorial | 1937 |
| Bayley Homes Ltd | Construction | 2025 |
| Bayley-Edge Limited | Manufacturing | 1980 |
| Baymore IT Solutions Ltd | Information & communication | 2018 |
| Bayse Reformer Pilates Altrincham Ltd | Other services | 2025 |
| Bayse Reformer Pilates Cardiff Ltd | Other services | 2025 |
| Bayse Reformer Pilates Liverpool Ltd | Other services | 2025 |
| Bayse Reformer Pilates Preston Ltd | Other services | 2025 |
| Bayse Reformer Pilates Stockton Heath Ltd | Other services | 2025 |
| Bayse Reformer Pilates Stoke Ltd | Other services | 2025 |
| Bayse Reformer Pilates Swansea Ltd | Other services | 2025 |
| Bayse Reformer Pilates Wilmslow Ltd | Other services | 2025 |
| Bazz 1 Limited | Hospitality | 2026 |
| BB L&D Solutions Ltd | Other services | 2019 |
| BBM Warrington Ltd | Wholesale & retail | 2021 |
| Bbmf Limited | Wholesale & retail | 2014 |
| Bbst Ltd | Administrative & support | 2015 |
| BC Accounts Ltd | Professional & scientific | 2011 |
| BC Homes Limited | Real estate | 2016 |
| Bchance Limited | Financial services | 2018 |
| BCR Property Developments Limited | Construction | 2017 |
| BCS Exhausts Ltd | Extraterritorial | 2021 |
| BD Construction Limited | Construction | 1998 |
| BD Roofing SW Ltd | Construction | 2025 |
| BDC Contractors Limited | Construction | 2010 |
| BDC External Insulation Systems Limited | Construction | 2020 |
| BDH Property Management Ltd | Construction | 2021 |
| BDK Creative Ltd. | Arts & recreation | 2026 |
| Bdlt Courier Services Limited | Other services | 2022 |