| AXY (2005) Limited | Wholesale & retail | 2005 |
| Ayjaytee Limited | Real estate | 2024 |
| Ayomide Enterprises Ltd | Other services | 2018 |
| AYP Financial Planning Limited | Extraterritorial | 2005 |
| AZ Scarborough Limited | Extraterritorial | 2010 |
| Azmarino Coffee Limited | Hospitality | 2021 |
| Aztec Engineering Consultants Ltd | Professional & scientific | 2026 |
| Azura Engineering Limited | Professional & scientific | 2011 |
| Azzurian Limited | Professional & scientific | 2024 |
| B & E Stores Ltd | Wholesale & retail | 2017 |
| B & J Storage Solutions Ltd | Arts & recreation | 2015 |
| B 4 a Enterprise Ltd | Wholesale & retail | 2017 |
| B Chambers Bowness Limited | Hospitality | 2022 |
| B Fibre Solutions Ltd | Administrative & support | 2019 |
| B Housemartin (UK) Limited | Real estate | 2014 |
| B&D Holding Services Ltd | Financial services | 2024 |
| B&J Homes Ltd | Construction | 2022 |
| B-Remedy Limited | Wholesale & retail | 2014 |
| B. Livesey Limited | Other services | 1934 |
| B.B. Joshua Ltd | Transport & logistics | 2019 |
| B.C Transport Ltd | Transport & logistics | 2014 |
| B.R.B. Industrial Services Limited | Professional & scientific | 1980 |
| B.T Property Solutions Ltd | Construction | 2021 |
| B2B Tills Limited | Wholesale & retail | 2015 |
| B2BTRADECARD Marketing Limited | Professional & scientific | 2016 |
| B3 Consult Ltd | Construction | 2023 |
| Baaa 38 Limited | Hospitality | 2022 |
| Baba's Takeaway Ltd | Hospitality | 2017 |
| Babushka Digital Ltd | Information & communication | 2016 |
| Babycurls Limited | Wholesale & retail | 2013 |
| Babylonian Associates Ltd | Information & communication | 2011 |
| Bachas Limited | Construction | 1994 |
| Back in Motion Limited | Health & social care | 2002 |
| Back to Brite Limited | Other services | 2014 |
| Backyard ZOO Limited | Information & communication | 2015 |
| Badger Plastering Ltd | Construction | 2025 |
| Baggy Cat Limited | Information & communication | 2011 |
| Bailcast Limited | Wholesale & retail | 1980 |
| Bailey Sports Therapy Limited | Arts & recreation | 2015 |
| Bailprint Holdings Limited | Professional & scientific | 2008 |
| Bailprint Labels Ltd | Manufacturing | 2001 |
| Bailprint SA Limited | Extraterritorial | 2008 |
| Baines Consultancy Limited | Professional & scientific | 2014 |
| Baines Operations Ltd | Water & waste | 2024 |
| Bairstow Living Limited | Households | 2016 |
| Bake & Shake Ltd | Manufacturing | 2025 |
| Balco Security Systems Ltd | Administrative & support | 2025 |
| Baldwin Joinery & Construction Ltd | Construction | 2017 |
| Ballachulish Rope and Slope Ltd | Construction | 2021 |
| Balmoral Gardens (Whittle LE Woods) Management Company Limited | Households | 2013 |
| Balti Express (Wessex) Ltd | Hospitality | 2018 |
| Baltic Wharf Holdings Limited | Real estate | 2025 |
| Bamba Healthcare Limited | Health & social care | 2024 |
| Bamba Homes Limited | Real estate | 2025 |
| Bamber Bridge Nutrition Ltd | Health & social care | 2025 |
| Bamford & Mccann Ltd | Wholesale & retail | 2015 |
| Bamfords Group Ltd | Wholesale & retail | 2026 |
| Bamfords Pharmacy Limited | Wholesale & retail | 2007 |
| Banbury Magistrates Court Limited | Construction | 2019 |
| Bancroft LEE Landscapes Limited | Administrative & support | 2020 |
| Baneswell Express Limited | Wholesale & retail | 2017 |
| Banks Surveyors Limited | Professional & scientific | 2026 |
| Bans Accounting Ltd | Professional & scientific | 2023 |
| Bar Booster Ltd | Administrative & support | 2026 |
| Bar VU Limited | Hospitality | 2012 |
| BAR42 Limited | Professional & scientific | 2013 |
| Baratrum Limited | Transport & logistics | 2025 |
| Barbarossa Online Limited | Wholesale & retail | 2024 |
| Barberesso Eccleston Ltd | Other services | 2024 |
| Barcelos Piri Piri Limited | Hospitality | 2018 |
| Bardsway Development Ltd | Real estate | 2026 |
| Bargain Convenience Stores Limited | Wholesale & retail | 2018 |
| Bargh Estates Limited | Construction | 2023 |
| Barley Farm Ltd | Other services | 2026 |
| Barlow Building Limited | Construction | 2021 |
| Barlow Fencing Limited | Real estate | 1998 |
| Barlow Properties (Preston) Ltd | Administrative & support | 2018 |
| Barnard and Green Limited | Real estate | 2017 |
| Barnes Hospitality Services Limited | Professional & scientific | 2025 |
| Barona Ltd | Health & social care | 2021 |
| Barrels and Beers Ltd | Hospitality | 2022 |
| Barrows and Forrester Property Group Ltd | Real estate | 2015 |
| Barrowway NO. 2 Limited | Financial services | 2015 |
| Barton Civil Engineering Limited | Construction | 2020 |
| Barton Holdings Ltd | Construction | 2019 |
| Barton IT Services Ltd. | Information & communication | 2017 |
| Barza Property Ltd | Real estate | 2024 |
| Base Construction & Maintenance Limited | Construction | 2013 |
| Base Engineering Services Ltd | Construction | 2020 |
| Base Property NW Ltd | Real estate | 2024 |
| Basetec Construction Limited | Construction | 2007 |
| Basetec Piling Ltd | Construction | 2010 |
| Bastion Estates Ltd | Construction | 2022 |
| Bateman Thermotooling (NW) Limited | Manufacturing | 2023 |
| Bates Property Consultants Limited | Professional & scientific | 2014 |
| Bath Property Solutions Ltd | Construction | 2019 |
| Bathroom Suites Northeast Ltd | Construction | 2017 |
| Bathroom Taps Direct Ltd | Wholesale & retail | 2025 |
| Bathrooms and Boilers Ltd | Construction | 2023 |
| Batt Holden Limited | Administrative & support | 2017 |