| Bookanexam Ltd | Education | 2019 |
| Bookarella Limited | Professional & scientific | 2016 |
| Booker Wellman (Properties) Limited | Real estate | 1988 |
| Booker Wellman Limited | Manufacturing | 1971 |
| Bookkeeping by BW Ltd | Professional & scientific | 2026 |
| Booklite Ltd | Information & communication | 2023 |
| Booktrust | Education | 1925 |
| Boom Audio Ltd | Information & communication | 2026 |
| Boom Bar Ltd | Hospitality | 2021 |
| Boomerang Deli Limited | Hospitality | 2019 |
| Boomerang Engineering Limited | Professional & scientific | 2016 |
| Boon Films Ltd | Administrative & support | 2017 |
| Boonmee Foods Ltd | Hospitality | 2023 |
| Booski Supplies Ltd | Wholesale & retail | 2026 |
| Boost EV Limited | Construction | 2020 |
| Boost Talent Ltd | Administrative & support | 2024 |
| Boot & Rally Limited | Hospitality | 2017 |
| Boot Bank Limited | Health & social care | 2011 |
| Boot Repair Company Limited | Wholesale & retail | 2011 |
| Bootfast Technologies Ltd | Extraterritorial | 2010 |
| Booth Loft Conversions and Building Services Limited | Construction | 2009 |
| Booth Mixer Hire Limited | Transport & logistics | 2016 |
| Booth Steel Stockholders Limited | Wholesale & retail | 1982 |
| Booth Transport Limited | Transport & logistics | 1980 |
| Bootham Place (Management Company) Limited | Households | 2002 |
| Bootham Terrace Management Company Limited | Households | 2019 |
| Boothferry Car & Commercials Limited | Wholesale & retail | 2024 |
| Booths Commercial Roofing and Cladding Ltd | Construction | 2021 |
| Bootle & Barrett Properties Ltd | Hospitality | 2026 |
| Booze 4 ALL Ltd | Wholesale & retail | 2024 |
| Booze N News Store Ltd | Wholesale & retail | 2013 |
| BOOZE2BAR Ltd | Hospitality | 2021 |
| BOOZE4U Leeds Ltd | Wholesale & retail | 2026 |
| BOP Trading Ltd | Wholesale & retail | 2005 |
| Border to Coast Pensions Partnership Limited | Financial services | 2017 |
| Border Welha Limited | Water & waste | 2015 |
| Bored Chaps Ltd | Information & communication | 2020 |
| Borehamwood Homes Ltd | Real estate | 2022 |
| Boride Services Limited | Professional & scientific | 2003 |
| Boris Software Limited | Information & communication | 2012 |
| Born and Raised Creative Ltd | Professional & scientific | 2010 |
| Born Holdings Limited | Professional & scientific | 2006 |
| Born Property (Residential) Limited | | 2008 |
| Born Ugly Associates Limited | Arts & recreation | 2020 |
| Born Ugly Limited | Arts & recreation | 1994 |
| Boro Lifts Ltd | Manufacturing | 2016 |
| Borough General Store Ltd. | Wholesale & retail | 2020 |
| Borrill Consulting Limited | Administrative & support | 2022 |
| Bors Consulting Limited | Information & communication | 2013 |
| Bosco Communications Limited | Information & communication | 2006 |
| Bosco Holdings Ltd | Financial services | 2019 |
| Bosco Investments Ltd | Real estate | 2023 |
| Boshton Lodge Limited | Real estate | 2024 |
| Boshu Ltd | Administrative & support | 2025 |
| Bosley Project Investments Limited | Administrative & support | 2020 |
| Boss Mercedes Ltd | Wholesale & retail | 2004 |
| Boss Networks Limited | Information & communication | 2014 |
| Bost Ltd | Wholesale & retail | 2024 |
| Bostanul Ltd | Real estate | 2017 |
| Boston Heritage Beds Limited | Professional & scientific | 1937 |
| Boston Installations Ltd | Construction | 2021 |
| Boston Insurance Brokers Limited | Financial services | 1994 |
| Boston Spa Aesthetics Ltd | Health & social care | 2025 |
| Boston Spa Property Services Ltd | Households | 2022 |
| Bosun Logistics Limited | Transport & logistics | 2013 |
| Bosworth Estates Limited | Real estate | 1937 |
| Botanical Enterprises (Publications) Limited | Information & communication | 1956 |
| Bothainna Limited | Real estate | 2022 |
| Botros & Co. Ltd. | Administrative & support | 2020 |
| Bottega Interiors Ltd | Construction | 2022 |
| Bottega Milanese Inc Limited | Hospitality | 2017 |
| Bottega Search Limited | Administrative & support | 2024 |
| Bottle & TAP Ltd | Hospitality | 2020 |
| Bottle Babes Ltd | Wholesale & retail | 2023 |
| Bottle Chop Ltd | Wholesale & retail | 2021 |
| Bottle Solutions Limited | Wholesale & retail | 2018 |
| Bottomley & Co Ltd | Other services | 2023 |
| Bould Brothers LLP | | 2019 |
| Boundary Ventures Ltd | Financial services | 2024 |
| Boundless Move Limited | Real estate | 2025 |
| Bountip Technologies Ltd | Information & communication | 2023 |
| Bousfield Limited | Real estate | 2025 |
| Boutique Cleaning Company Ltd | Administrative & support | 2019 |
| Boutique SEO Limited | Professional & scientific | 2025 |
| Bova Developments Ltd | Construction | 2023 |
| Bovi Properties Ltd | Real estate | 2017 |
| Bovingdon Self-Build Limited | Extraterritorial | 2016 |
| BOW Design and Print Limited | Manufacturing | 2003 |
| BOW Fire Ltd | Public administration | 2021 |
| Bowa Properties Limited | Real estate | 2020 |
| Bowcliffe (Leeds) Limited | Real estate | 2012 |
| Bowcliffe Trinity Limited | Real estate | 2014 |
| Bowerfield House Limited | Health & social care | 1988 |
| Bowery Visual Arts Limited | Arts & recreation | 2007 |
| Bowl of Joy Ltd | Hospitality | 2022 |
| Bowland Brooks Environment Limited | Professional & scientific | 2020 |
| Bowland House Psychiatry Limited | Health & social care | 2026 |
| Bowlers Court Ltd | Health & social care | 2013 |
| Bowling Green Yard Management Co. Ltd | Real estate | 2022 |
| Bowlsbridge | Households | 1998 |