| Bistep Ltd | Hampton | 2016 |
| BIT of Extra DOE Limited | Stockbridge | 2024 |
| BIT of Extra Dough Limited | Stockbridge | 2024 |
| Bita Cosmetics Limited | Thornton Heath | 2010 |
| Bitbuzz UK Limited | Reading | 2012 |
| Bitcapital Ltd. | London | 2014 |
| Bitcliff Ltd | London | 2020 |
| BITCO1N Cash Limited | Harrogate | 2021 |
| Bitcoin Holding Ltd | London | 2023 |
| Bitcoin Lounge Ltd | Kington | 2020 |
| Bitcoin News Ltd | Bristol | 2024 |
| Bitcoin Scotland Ltd | Ayr | 2022 |
| Bite-Size Plays Limited | Brighton | 2007 |
| Bites With Hope UK Ltd | Bedford | 2021 |
| Bitesize Tax Ltd | Calne | 2019 |
| Bitflow Investments 427 Limited | Eastbourne | 2015 |
| Bithells Limited | Bolton | 2009 |
| Bithrey (Developments) Limited | Devon | 1981 |
| Bitik Ltd | Upper Belvedere | 2017 |
| Bitmuseum Limited | Huntingdon | 2015 |
| Bitronix Cryptoworks Limited | Carrickfergus | 2018 |
| Bits'N'Bobs Ltd | Salford | 2003 |
| Bitshop Ltd | London | 2018 |
| Bitstop Limited | London | 1998 |
| Bitten LIP Clothing Ltd | Poole | 2020 |
| Bittens Syrum Invest Limited | London | 2022 |
| Bittens Syrum Limited | London | 2022 |
| Bittern Management Company Limited | Exeter | 1989 |
| Bittersweet Partnership Limited | Burton Upon Trent | 1965 |
| Bittylicious Ltd | London | 2013 |
| Bitumen Property Letting Ltd | Rossendale | 2017 |
| Bitus Wood Products Limited | Rochford | 2018 |
| Biurokrat Ltd | Crewe | 2018 |
| Biydirect.Com Limited | West Midlands | 2000 |
| BIZ Advisors Ltd | Harrow | 2016 |
| BIZ Expert Limited | Leighton Buzzard | 2020 |
| BIZ SRS Limited | Luton | 2018 |
| BIZ Stationery Limited | Newent | 2019 |
| Bizetta Yachting Ltd | London | 2024 |
| Bizflex Limited | Godalming | 2012 |
| Bizibees Limited | Bournemouth | 2002 |
| Bizify Ltd | Middlesbrough | 2015 |
| Bizness Investments PLC | Dover | 2011 |
| Biznify Investment Limited | London | 2011 |
| Biznify Limited | London | 2009 |
| Bizsheet Ltd | Harrow | 2015 |
| Bizspace Developments Limited | London | 2016 |
| Bizum Ltd | London | 2025 |
| Bizztrak Limited | Worcester | 2009 |
| Bizzy Systems Limited | Rickmansworth | 1998 |
| BJ Aviation Consultants Ltd | London | 2013 |
| BJ Bajabaa Import and Export Company Limited | London | 2024 |
| BJ Construction Services Ltd | Gravesend | 2015 |
| Bj's 2010 Limited | Swansea | 2010 |
| Bjark Ltd | Glasgow | 2023 |
| BJB Consultancy Services Ltd | Barnsley | 2016 |
| BJB Systems Ltd | Peterhead | 2024 |
| BJD Processing Limited | Wakefield | 2024 |
| Bjere Barnservice Limited | London | 2024 |
| BJJ Nutrition Ltd | Clevedon | 2023 |
| Bjkc 2 Limited | Gloucester | 2023 |
| BJL Engineering Services (Shang HAI) Co., Limited | West Midlands, England, | 2023 |
| BJM Investment Management Ltd | Coventry | 2013 |
| Bjork Sweden Invest Limited | London | 2023 |
| Bjorkmans Ljussmycken Limited | London | 2020 |
| Bjorn Borg UK Limited | Warwick | 2010 |
| Bjornen-Schysstkok Invest Limited | London | 2025 |
| Bjornen-Schysstkok Limited | London | 2025 |
| BJP Investment Management Ltd | Edinburgh | 2012 |
| BJT Accountants Limited | Winchester | 2016 |
| BJX 4 Limited | Clayton Le Moors | 2013 |
| BK Consultinguk Ltd | Huddersfield | 2023 |
| BK Newco Ltd | Bracknell | 2019 |
| BK Plus (Cheltenham) Limited | Walsall | 1997 |
| BK Plus (Falkirk) Limited | Dundee | 2021 |
| BK Plus (Solihull) Limited | Walsall | 2000 |
| BK Plus (ST Helens) Limited | Walsall | 2019 |
| BK Plus (Stoke) Limited | Walsall | 2015 |
| BK Plus High Wycombe Limited | Walsall | 2010 |
| BK5 Services Ltd | London | 2019 |
| Bkasz Ltd | Grays | 2022 |
| BKL Advisory Limited | London | 2025 |
| BKL Company Services Ltd | London | 2017 |
| BKL Contact Sports Ltd | Glasgow | 2022 |
| BKL Group Limited | London | 2025 |
| BKL Limited | London | 2025 |
| BKL Security Limited | Witham | 2019 |
| Bklove Ltd | London | 2024 |
| BKM Marketing Limited | Wilmslow | 2016 |
| BKS Ventures Limited | London | 2014 |
| BKT Aero Ltd | Dromore | 2025 |
| BKT Group Holdings Limited | Kent | 1994 |
| BL Holding SWE Limited | London | 2020 |
| BL Ltd | Newmarket | 2009 |
| BL Retail Properties 2 Limited | London | 2021 |
| BL Retail Properties Limited | London | 2021 |
| BL Retail Property Holdings Limited | London | 2021 |
| BL UK Investments Limited | Coventry | 2024 |
| BL1SS Ltd | Manchester | 2020 |
| BLA 2059 Limited | Reading | 2016 |