| Bahia Diego Ltd | Administrative & support | 2021 |
| Bahja Investment Ltd | Real estate | 2026 |
| BAI LE LAI Limited | Hospitality | 2025 |
| Baiceir Limited | Construction | 2014 |
| Baichuang Foreign Trade Ltd | Wholesale & retail | 2024 |
| Baid.Org.Uk Ltd | Health & social care | 2012 |
| Baig Business Associates Ltd | Professional & scientific | 2017 |
| Baii Logisitics Limited | Wholesale & retail | 2018 |
| Bailey Building and Roofing Limited | Construction | 2009 |
| Bailey Hodge Investments Limited | Professional & scientific | 2007 |
| Bailey Power Ltd | Construction | 2026 |
| Bailey Property Law Limited | Professional & scientific | 2019 |
| Bailey Thomas Limited | Education | 2019 |
| Bain Global Management Ltd | Other services | 2021 |
| Baines Trend Ltd | Wholesale & retail | 2025 |
| Baird's Communications Management Consultants Ltd | Professional & scientific | 2003 |
| Baish Ltd | Hospitality | 2024 |
| Bait Albinaa Trading Ltd | Wholesale & retail | 2025 |
| Baiteze Squad Limited | Arts & recreation | 2017 |
| Bajrangi Developments Limited | Real estate | 2023 |
| BAK Holdings Limited | Other services | 2019 |
| Bakar Skoljka Limited | Hospitality | 2023 |
| Bake ME Happy Limited | Hospitality | 2018 |
| Bake N’ Flake Limited | Manufacturing | 2025 |
| Bakehouse Content Studio Ltd | Information & communication | 2026 |
| Bakehouse Llantwit Major Ltd | Hospitality | 2026 |
| Bakeorama Limited | Manufacturing | 2015 |
| Baker Bespoke Limited | Manufacturing | 2021 |
| Baker Bros Property Ltd | Financial services | 2024 |
| Baker Geological Services Ltd | Professional & scientific | 2015 |
| Baker Street Partners Limited | Financial services | 2025 |
| Baker Street Recruitment Ltd | Professional & scientific | 2025 |
| Baker Street Technologies Limited | Professional & scientific | 2010 |
| Bakerley PC | | 2018 |
| Bakers Court Management Limited | Households | 1983 |
| Bakers Food Limited | Manufacturing | 2024 |
| Bakery & Sweets Limited | Wholesale & retail | 2024 |
| Bakery Treat Boxes Ltd | Hospitality | 2022 |
| Bakesense Bakeries Limited | | 2006 |
| Bakewell Ventures Limited | Information & communication | 2024 |
| Bakhoor Ltd | Wholesale & retail | 2025 |
| Bakhshandco Limited | Professional & scientific | 2025 |
| Bakhtar Catering Limited | Hospitality | 2016 |
| Baking the Books Limited | Information & communication | 2015 |
| Bakir & Co. Estates Ltd | Real estate | 2025 |
| Bakri & Brothers Limited | Other services | 2023 |
| BAL Digital Ltd | Wholesale & retail | 2023 |
| Bala Gold Ltd | Manufacturing | 2023 |
| Bala JI (Developments) Limited | Real estate | 2011 |
| Balaklava 1968 Ltd | Professional & scientific | 2024 |
| Balam (Cardiff) Ltd | Wholesale & retail | 2026 |
| Balance Limited | Hospitality | 2026 |
| Balance Marketing Ltd | Professional & scientific | 2023 |
| Balance Search Limited | Information & communication | 2017 |
| Balance Your World Ltd | Wholesale & retail | 2018 |
| Balancebliss Wellness Ltd | Arts & recreation | 2024 |
| Balanced Aesthetics Limited | Health & social care | 2024 |
| Balancepro Solutions Ltd | Administrative & support | 2025 |
| Balar Ltd | Wholesale & retail | 2024 |
| Balbourne Renewable Investments Limited | Administrative & support | 2010 |
| Balcells GAL Ltd | Information & communication | 2025 |
| Balci Line Limited | Wholesale & retail | 2021 |
| Balcroft Brickwork Ltd | Administrative & support | 2016 |
| Baldwinlogistics Ltd | Wholesale & retail | 2024 |
| Baldwins Travel Agency Limited | Administrative & support | 1991 |
| Bale and Thomas Ltd | Administrative & support | 2023 |
| Balesford Ltd | Real estate | 2018 |
| Bali Store Limited | Wholesale & retail | 2025 |
| Balinor Group Holdings Limited | Real estate | 2016 |
| Balinor Property Management Limited | Real estate | 2016 |
| Baljeet SINGH1 Ltd | Construction | 2025 |
| Baljit Singh Balli Limited | Construction | 2023 |
| Ball & Co Surveyors Limited | Professional & scientific | 2018 |
| Ball Bay Lettings Ltd | Real estate | 2020 |
| Ball RD Properties Limited | Real estate | 2021 |
| Ballantines LLP | | 2022 |
| Ballards Natural Dog Treats Ltd | Wholesale & retail | 2023 |
| Ballarino Limited | Other services | 2004 |
| Ballonz Ltd | Professional & scientific | 2025 |
| Balloons by Pippa Limited | Administrative & support | 2018 |
| Ballson Collective Limited | Real estate | 2022 |
| Bally Commodities Limited | Water & waste | 2026 |
| Ballyhahill Constructions Ltd | Construction | 2020 |
| Ballykeel Ltd | Professional & scientific | 2024 |
| Balm Investments LP | | 2017 |
| Balmcrest Homes Limited | Real estate | 2004 |
| Balmoral Quays (Apartments) Management Company Limited | Households | 2007 |
| Balneo Bathrooms Ltd | Manufacturing | 2013 |
| Baloch Mart Ltd | Wholesale & retail | 2025 |
| Baloch Services Ltd | Wholesale & retail | 2025 |
| Balog Trading Ltd | Wholesale & retail | 2022 |
| Balome Ltd | Wholesale & retail | 2021 |
| Baloo Medee Exchange Ltd | Administrative & support | 2019 |
| Balrey Screen Printing 1 Ltd | Administrative & support | 2020 |
| Balrey Screen Printing 2 Ltd | Administrative & support | 2023 |
| Balrey Screen Printing 3 Ltd | Administrative & support | 2022 |
| Balrey Screen Printing 4 Ltd | Administrative & support | 2020 |
| Balrosegue Ltd | Wholesale & retail | 2025 |
| Balsamee Ltd | Information & communication | 2014 |
| Balti Master(Cardiff) Ltd | Hospitality | 2013 |