| Bobek Trans Ltd | Transport & logistics | 2026 |
| Bochniak Transport Ltd | Transport & logistics | 2019 |
| Bodies by Naomi Ltd | Other services | 2024 |
| Body AID Solutions Ltd | Education | 2011 |
| Bodyglow Fitness Ltd | Other services | 2026 |
| Bodymindandsole Ltd | Other services | 2019 |
| Bogdan and Marian Transportation Ltd | Transport & logistics | 2025 |
| Bogdan B Logistics Ltd | Transport & logistics | 2018 |
| Bogle Support Services Limited | Administrative & support | 2023 |
| Boika Ltd | Transport & logistics | 2016 |
| Boors Ltd | Construction | 2016 |
| Bora LA Aprender Ltd | Manufacturing | 2025 |
| Boro Logistics Ltd | Transport & logistics | 2019 |
| Boston Bulbs Wholesale Limited | Extraterritorial | 2014 |
| Boston Flower Bulbs Limited | Extraterritorial | 2019 |
| Boston Group Holding Ltd | Information & communication | 2015 |
| Boston Home Improvements Ltd | Construction | 2022 |
| Boston ISM Catering Ltd | Administrative & support | 2019 |
| Boston Tractors Limited | Real estate | 1948 |
| Bottomwood Shoot Limited | Arts & recreation | 2021 |
| Boud Holdings Ltd | Financial services | 2023 |
| Bouffant Betty Limited | Arts & recreation | 2016 |
| Bounce House Party Ltd | Administrative & support | 2025 |
| Bouncing Bean Limited | Professional & scientific | 2020 |
| Bourne Ceramic & Bathrooms Limited | Construction | 2025 |
| Bourne to Gleam Ltd | Administrative & support | 2025 |
| Boutique of Beauty Ltd | Wholesale & retail | 2022 |
| Bower Commercials (Lincs) Ltd | Wholesale & retail | 2024 |
| Bowers Fleming & Co. Limited | Professional & scientific | 2003 |
| Bowman Family Investment Company | Financial services | 2022 |
| Boxes of Hope CIC | Health & social care | 2022 |
| BQV Produce Limited | Professional & scientific | 1999 |
| BR Takeaway Ltd | Hospitality | 2024 |
| Brackenbarn Limited | Real estate | 1980 |
| Brackmills Roofing Services Ltd | Construction | 2026 |
| Bradley James Estate Agents Limited | Real estate | 2024 |
| Bragulis Ltd | Transport & logistics | 2023 |
| Brandedon Logistics Ltd | Wholesale & retail | 2024 |
| Bravo Accounts Ltd | Professional & scientific | 2026 |
| Braxton & Cole Estates Limited | Construction | 2025 |
| Braybrooks Bros. Limited | Agriculture & fishing | 1947 |
| Brayfields Management Company Limited | Households | 1994 |
| BRB Developments (Lincs) Ltd | Construction | 2024 |
| Breakthrough Therapy Solutions Ltd. | Education | 2019 |
| Breaze Health Ltd | Manufacturing | 2018 |
| Breeder Imaging Services Ltd | Administrative & support | 2020 |
| Brent Edward Homes Limited | Construction | 2023 |
| Brentford Marine Services Limited | Arts & recreation | 2005 |
| Bretburn Ltd | Construction | 2025 |
| BRG Utilities & Construction Ltd | Construction | 2023 |
| Brick Nest Homes Limited | Construction | 2026 |
| Bridge Farm (Bicker) Ltd | Real estate | 2013 |
| Bridge Farm Group Limited | Financial services | 2020 |
| Bridge Farm Holdco Limited | Professional & scientific | 2017 |
| Bridge Farm Holdings Ltd | Real estate | 2017 |
| Bridge Farm Horticulture Limited | Administrative & support | 2011 |
| Bridge Farm Marketing Limited | Agriculture & fishing | 2025 |
| Bridge Farm Property Limited | Professional & scientific | 2017 |
| Bridge Greenhouses Limited | Construction | 1982 |
| Bridge Hardware (SB) Ltd | Wholesale & retail | 2024 |
| Bridge House Antiques (Sutton Bridge) Limited | Wholesale & retail | 2003 |
| Bridge Investments (U.K) Limited | Other services | 2022 |
| Bridge Road Chippy Ltd | Hospitality | 2026 |
| Bridge Street SPV Ltd | Construction | 2019 |
| Bridle Products (K9) Ltd | Wholesale & retail | 2016 |
| Bright Business Support Limited | Extraterritorial | 2021 |
| Brightshine Window Cleaning Ltd | Administrative & support | 2023 |
| Brightview Holdings Limited | Financial services | 2025 |
| Brisan Properties Ltd | Real estate | 2025 |
| Bristruc International Ltd | Professional & scientific | 2025 |
| British American Investments Limited | Real estate | 1995 |
| Brittain Electrical Ltd | Construction | 2023 |
| Broad Street 2026 Limited | Extraterritorial | 2000 |
| Broadbent Construction Limited | Construction | 2026 |
| Broadgate Affordable Limited | Financial services | 2005 |
| Broadgate Developers Limited | Construction | 1999 |
| Broadgate Logistics Ltd | Transport & logistics | 2023 |
| Broadgate Property Ltd | Real estate | 2023 |
| Broadview Consulting Ltd | Information & communication | 2025 |
| Broadway Hair Limited | Other services | 2011 |
| Brock Business Limited | Administrative & support | 2011 |
| Brockbarn Ltd | Professional & scientific | 2014 |
| Brockdale Ltd | Agriculture & fishing | 2017 |
| Broderick Property Holdings Ltd | Real estate | 2026 |
| Brodie Russell Electrical Limited | Manufacturing | 2015 |
| Bromley Memorial Hall Limited | Health & social care | 1958 |
| Brookhouse Hypnotherapy Limited | Health & social care | 2004 |
| Brookhouse Training and Consultancy Ltd | Extraterritorial | 2021 |
| Brooks Spalding (Holdings) Limited | Financial services | 2026 |
| Brooky’S Driving School Ltd | Education | 2022 |
| Brownmoor Developments (Long Sutton) Ltd | Construction | 2024 |
| Bruart Ltd | Transport & logistics | 2019 |
| Brun LEA Care Ltd | Administrative & support | 2002 |
| Brunswick Fields Management Company Ltd | Households | 2021 |
| Bryan Linn Limited | Professional & scientific | 2017 |
| Bsba Properties Limited | Real estate | 2012 |
| BSH Welding and Fabrication Limited | Manufacturing | 2025 |
| BSO 1 Holdings Limited | Financial services | 2026 |
| BT Blinds Limited | Construction | 2024 |
| Btracts Limited | Extraterritorial | 1997 |