| Balance Psychiatry Limited | Health & social care | 2023 |
| Balanceology Ltd | Professional & scientific | 2022 |
| Balas Transport Limited | Transport & logistics | 2014 |
| Baldwin Barbers Ltd | Other services | 2024 |
| Baldwin Finance Limited | Real estate | 1972 |
| Bale & Mawson Ltd | Health & social care | 2026 |
| Bale Joinery Ltd | Manufacturing | 1999 |
| Bale Property Developments Limited | Real estate | 2021 |
| Balecom Limited | Wholesale & retail | 1999 |
| Balefire Digital Ltd | Professional & scientific | 2023 |
| Balendin Property Ltd | Real estate | 2020 |
| Bales Kitchens Limited | Construction | 2007 |
| Ball Living Ltd | Real estate | 2013 |
| Ball Property One Ltd | Real estate | 2021 |
| Ballantyne Technology Associates Limited | Administrative & support | 2022 |
| Ballard Consulting Ltd | Construction | 2022 |
| Ballcraft Limited | Extraterritorial | 1999 |
| Balli's Ltd | Wholesale & retail | 2020 |
| Ballistic Communications Ltd | Administrative & support | 2015 |
| Balloon Letting Company Ltd | Real estate | 2020 |
| Balloontastic Portishead Ltd | Arts & recreation | 2019 |
| Ballotset Limited | Households | 1989 |
| Ballyhoo Clothing Company Limited | Wholesale & retail | 2000 |
| Balmain Studio Limited | Manufacturing | 2021 |
| Balmoral Fire and Security Limited | Extraterritorial | 2025 |
| Balmoral Heights (Management) Company Limited | Households | 2002 |
| Balmoral Systems Limited | Construction | 2002 |
| Balmspace Limited | Wholesale & retail | 2024 |
| Balneo Installation Limited | Construction | 2016 |
| Baloo’S RAW Food Limited | Wholesale & retail | 2025 |
| Balsh's House and Home Decorating Services Ltd | Construction | 2025 |
| Baltfast Ltd | Transport & logistics | 2022 |
| Balti Catering Ltd | Hospitality | 2019 |
| Baltic Bakery Service Limited | Other services | 2011 |
| Baltic Comfort Ltd | Information & communication | 2025 |
| Baltic Cuisine Ltd | Hospitality | 2025 |
| Baltic Timber Products Limited | Construction | 2016 |
| Baltic Wharf Management Company Limited | Households | 1984 |
| Balticgp Health Support Ltd | Health & social care | 2021 |
| Baltika Euro Ltd | Wholesale & retail | 2023 |
| Baltimore Consulting Limited | Administrative & support | 2013 |
| Baltimore Holdings Limited | Financial services | 2018 |
| Balvex Ltd | Transport & logistics | 2026 |
| BAM Boom Cloud Limited | Information & communication | 2019 |
| Bama British Academy of Medical Aesthetics Limited | Education | 2017 |
| Bamber Education Limited | Administrative & support | 2019 |
| Bambi Locks Extensions Limited | Other services | 2022 |
| Bambinos & Bandits Ltd | Wholesale & retail | 2023 |
| Bamboo Cloud Holdings Limited | Financial services | 2020 |
| Bamboo Consultants Ltd | Professional & scientific | 2018 |
| Bamboo Platform Services Limited | Administrative & support | 2019 |
| Bambridge Electrical Ltd | Construction | 2018 |
| Bambury Metal Fabrications Limited | Manufacturing | 2002 |
| Bamfield Court Management Company Limited | Households | 2009 |
| Bamfield Tree Services Limited | Agriculture & fishing | 2023 |
| Bamh Investments Ltd | Real estate | 2016 |
| Bamlay Consulting Limited | Professional & scientific | 2017 |
| Bamley Homes (Parson) Limited | Real estate | 2025 |
| Bamley Homes Ltd | Construction | 2023 |
| Bamm (Holdings) Limited | Financial services | 2017 |
| Bamm Property Limited | Real estate | 2022 |
| Bamo Bristol Ltd | Wholesale & retail | 2024 |
| Bampf Ltd | Wholesale & retail | 2009 |
| Bampton Developments Ltd | Construction | 2014 |
| Bamsi Properties Limited | Real estate | 2023 |
| Bana Barber U.K Ltd | Other services | 2023 |
| Bana Dessert Ltd | Hospitality | 2025 |
| Banana Fingers Limited | Wholesale & retail | 2007 |
| Banana Island Ltd | Wholesale & retail | 2020 |
| Bananda Limited | Financial services | 2008 |
| Banazcorp Ltd | Real estate | 2024 |
| Banbury Carpentry South West Limited | Construction | 2017 |
| Banbury Power Limited | Energy | 2017 |
| Bandbreeze Limited | Real estate | 2000 |
| Bandrest Limited | Professional & scientific | 1987 |
| Bandwagon Tours Ltd | Administrative & support | 2024 |
| Bandwidth People Limited | Professional & scientific | 2023 |
| Banes Coaching Group Limited | Professional & scientific | 2023 |
| Banff Securities Limited | Construction | 1962 |
| Banfield Joinery Ltd | Manufacturing | 2023 |
| Banfield Studios Ltd | Administrative & support | 2024 |
| Bang IT UP Limited | Real estate | 2021 |
| Banging Burritos Ltd | Hospitality | 2025 |
| Bangs Workshop Limited | Other services | 2014 |
| Bangshanky Limited | Other services | 2024 |
| Banica Limited | Other services | 2019 |
| Bank of Ireland Britain Holdings Limited | Financial services | 1986 |
| Bank of Ireland Home Mortgages Limited | Professional & scientific | 1973 |
| Bankable Systems Ltd | Information & communication | 2007 |
| Banks-White Construction Ltd | Construction | 2025 |
| Banmain Limited | Real estate | 1986 |
| Bann the Writer Ltd | Information & communication | 2015 |
| Banner Estates Limited | Professional & scientific | 1996 |
| Bannerman Properties Limited | Real estate | 2005 |
| Bannostile Limited | Construction | 1976 |
| Bantacookie Ltd | Information & communication | 2018 |
| Banwell Garage Limited | Extraterritorial | 2006 |
| Banyan and Fieldfare Limited | Professional & scientific | 2014 |
| Banyan Care Holdings Limited | Financial services | 2022 |
| Banyan Care Homes 2 Limited | Health & social care | 2021 |