| B.P Data Networks Ltd | Construction | 2018 |
| B.R.S. Building Services Ltd | Construction | 2017 |
| B.Rad Creative Ltd | Professional & scientific | 2026 |
| B2B Synergy LLP | | 2016 |
| B2C Rides Ltd | Transport & logistics | 2024 |
| BA Building Supplies Ltd | Wholesale & retail | 2024 |
| Babich Limited | Real estate | 2006 |
| Baby BOY Limited | Administrative & support | 2021 |
| Babymoov UK Ltd | Wholesale & retail | 2015 |
| Bacirubati Ltd | Wholesale & retail | 2008 |
| Back at Ease Limited | Health & social care | 2016 |
| Backyard Farm Ltd | Wholesale & retail | 2023 |
| Badger Street Properties Limited | Real estate | 2001 |
| Bagber Ltd | Agriculture & fishing | 2019 |
| Bagmore Limited | Agriculture & fishing | 2019 |
| Bagzz S/W Ltd | Transport & logistics | 2022 |
| Bailey and Jones Limited | Construction | 2014 |
| Bailhache Law Limited | Professional & scientific | 2019 |
| Bainbridge Asbestos Services Limited | Education | 2010 |
| Bajwa Food Ltd | Hospitality | 2020 |
| Baker Ruff Hannon LLP | | 2015 |
| Bakerbrand Design Limited | Professional & scientific | 2022 |
| Baking (UK) Limited | Wholesale & retail | 2013 |
| Balance Collective Limited | Wholesale & retail | 2026 |
| Balancecare Limited | Information & communication | 2009 |
| Balanced Grid Works Limited | Construction | 2018 |
| Balancing I.T. Limited | Information & communication | 2016 |
| Baldbros Ltd | Wholesale & retail | 2021 |
| Baldinnie Developments Limited | Construction | 2016 |
| Ballantine Wealth Management Limited | Financial services | 2018 |
| Ballinger Holdings Limited | Wholesale & retail | 2023 |
| Banner Studio Construction Limited | Construction | 2014 |
| Bannisters Criminal and Motoring Lawyers LLP | | 2022 |
| Bansie Beheer Limited | Professional & scientific | 2010 |
| Baptista Enterprise Limited | Wholesale & retail | 2025 |
| Bar Bidco Limited | Financial services | 2023 |
| Barbican and White Lane Management Limited | Households | 2019 |
| Bardene Financial Limited | Professional & scientific | 2016 |
| Bare Grills Taunton Ltd | Hospitality | 2016 |
| Barnard Microsystems Limited | Professional & scientific | 1986 |
| Barnes Contracting Ltd | Agriculture & fishing | 2022 |
| Barnston Farms (Dorset) Limited | Real estate | 2006 |
| Barnyard Aluminium Ltd | Manufacturing | 2018 |
| Barratt & Canniford Holdings Ltd | Financial services | 2023 |
| Barratt and Canniford Limited | Construction | 1988 |
| Barrington Associates (South West) Limited | Professional & scientific | 2007 |
| Barrington Mews Management Company Limited | Households | 2007 |
| Barry Spiller Accounting Ltd | Professional & scientific | 2014 |
| Bartletts House Management Company Limited | Real estate | 2013 |
| Barton Grange Management Limited | Households | 1987 |
| Barton Grange Properties Limited | Construction | 2014 |
| Barton House Asset Management Limited | Real estate | 2012 |
| Barton Services (South West) Limited | Construction | 2003 |
| Basecrown Residents Association Limited | Households | 1983 |
| Basilgrange Limited | Households | 1983 |
| Basilico Inn Limited | Hospitality | 2025 |
| Basilisk Dynamics Limited | Manufacturing | 2025 |
| Basket Case Holdings Limited | Information & communication | 2022 |
| Basten Science & Software Beheer Limited | Administrative & support | 2012 |
| Basten Science & Software LLP | | 2012 |
| BAT Consultancy Ltd | Construction | 2025 |
| Batch Consulting Ltd | Wholesale & retail | 2023 |
| Batch Enterprises Ltd | Wholesale & retail | 2022 |
| Batch Hold Ltd | Wholesale & retail | 2023 |
| Bates&Misons Ltd | Construction | 2014 |
| Bath & West Properties Ltd | Real estate | 2023 |
| Bath Heritage Building Ltd | Construction | 2019 |
| Bath House & Bath House Court Management Company Limited | Households | 1984 |
| Bath Spa Dentistry Ltd | Health & social care | 2009 |
| Bathealton Court Limited | Hospitality | 2017 |
| Bathpool Car Wash Ltd | Wholesale & retail | 2026 |
| Bathpool Flooring Ltd | Wholesale & retail | 2021 |
| Bathpool Hand Car Wash Ltd | Administrative & support | 2020 |
| Batian Aerospace Consultancy Ltd | Professional & scientific | 2023 |
| Batten Property and Investments Limited | Real estate | 2024 |
| Batts Farm Management Company Limited | Households | 2022 |
| Bauhaus Psychology Ltd | Health & social care | 2024 |
| Bavent Asset Management Ltd | Real estate | 2018 |
| Bawden Cleaning Services Ltd | Administrative & support | 2011 |
| BAX Advocaten EN Mediators LLP | | 2015 |
| Bay Point Properties Limited | Real estate | 2025 |
| Bayberry Limited | Health & social care | 2009 |
| Bayer Developments Limited | Construction | 2013 |
| Baylair Limited | Professional & scientific | 2004 |
| Bayside Court Flat Management Company Ltd | Households | 2020 |
| BB Building Services SW Limited | Construction | 2020 |
| Bbco Ltd | Administrative & support | 2019 |
| BBQ Lodges Limited | Construction | 2005 |
| BCO Properties Limited | Real estate | 2017 |
| Bcreative Hair Limited | Other services | 2020 |
| BD DEV Ltd | Information & communication | 2025 |
| BDT Trading Ltd. | Professional & scientific | 2018 |
| BE Addressable Limited | Administrative & support | 2009 |
| BE Motors Ltd | Wholesale & retail | 2020 |
| Beach Holidays France Ltd | Hospitality | 2021 |
| Beachside Holiday Park Limited | Hospitality | 2018 |
| Beacon Vetcare Limited | Professional & scientific | 2020 |
| Beadmaster Limited | Manufacturing | 1994 |
| Beaming Restorations Ltd | Administrative & support | 2015 |
| Beamish Orthopaedics Ltd | Health & social care | 2022 |