| Blue Bricks Magazine Ltd | Information & communication | 2020 |
| Blue Catalyst Limited | Professional & scientific | 2017 |
| Blue Chip Property Ltd | Real estate | 2020 |
| Blue Consultants Limited | Financial services | 2017 |
| Blue COW Cables Ltd | Information & communication | 2011 |
| Blue Crush Limited | Hospitality | 2007 |
| Blue Diamond Products Limited | Wholesale & retail | 2000 |
| Blue Digital Group Ltd | Information & communication | 2016 |
| Blue Ducks Limited | Professional & scientific | 2001 |
| Blue Energy Brokers Limited | Energy | 2017 |
| Blue Flower Properties Ltd | Real estate | 2022 |
| Blue Granary Wharf (Leeds) Management Company Limited | Households | 2004 |
| Blue Hawk Consultancy Limited | Information & communication | 2015 |
| Blue Head Consultancy Limited | Information & communication | 2017 |
| Blue I Event Technology Limited | Administrative & support | 2002 |
| Blue I Group Limited | Financial services | 2016 |
| Blue I Holdings Limited | Financial services | 2022 |
| Blue I Technology Limited | Extraterritorial | 2021 |
| Blue I Theatre Technology Limited | Professional & scientific | 2015 |
| Blue Inc Kent Ltd | Hospitality | 2020 |
| Blue Investments Leeds Limited | Construction | 2024 |
| Blue J Pictures Ltd | Information & communication | 2024 |
| Blue Kite Group Ltd | Financial services | 2023 |
| Blue Kite Projects Limited | Professional & scientific | 2019 |
| Blue Kiwii Ltd | Wholesale & retail | 2024 |
| Blue Latan Ltd | Hospitality | 2023 |
| Blue Letts Limited | Real estate | 2009 |
| Blue Line Car Sale Ltd | Wholesale & retail | 2026 |
| Blue Lizard Books Ltd | Information & communication | 2019 |
| Blue Medical Services Ltd | Health & social care | 2019 |
| Blue Nails and Spa LS2 Ltd | Other services | 2024 |
| Blue Nile Shop Limited | Wholesale & retail | 2021 |
| Blue Note Clothiers Limited | Wholesale & retail | 2018 |
| Blue Oak Land Ltd | Construction | 2025 |
| Blue Ocean Capital Properties Ltd | Construction | 2026 |
| Blue Oxygen Ltd | Professional & scientific | 2018 |
| Blue Pavilion Ltd | Hospitality | 2020 |
| Blue Pepper Catering Ltd | Hospitality | 2013 |
| Blue Ribbon (Hull Developments) Limited | Real estate | 2006 |
| Blue Ribbon Property Management Limited | Real estate | 2013 |
| Blue Rice Ltd | Administrative & support | 2017 |
| Blue Rinse Holdings Limited | Financial services | 2016 |
| Blue Rinse Limited | Wholesale & retail | 2002 |
| Blue Rose Law Limited | Professional & scientific | 2023 |
| Blue Sakura Ltd | Hospitality | 2017 |
| Blue Sakura Manchester Ltd | Hospitality | 2024 |
| Blue Skies Roofing Company Limited | Construction | 2025 |
| Blue Sky (Armley) Limited | Wholesale & retail | 2024 |
| Blue Sky Coaches Limited | Extraterritorial | 2015 |
| Blue Sky Construction Limited | Wholesale & retail | 2007 |
| Blue Sky Leisure (Leeds) Ltd | Hospitality | 2017 |
| Blue Sky Sports Foundation Ltd | Health & social care | 2022 |
| Blue Sky Takeaway Ltd | Hospitality | 2025 |
| Blue Space FAV Ltd | Professional & scientific | 2018 |
| Blue Spices Zanzibar UK Limited | Wholesale & retail | 2025 |
| Blue Springs Properties Limited | Real estate | 2025 |
| Blue Square Brewery Limited | Manufacturing | 2020 |
| Blue Square Cleaning Ltd | Other services | 2021 |
| Blue Star Inns Limited | Wholesale & retail | 2005 |
| Blue Star Oracle Ltd | Health & social care | 2026 |
| Blue Star Quality & Compliance Ltd | Professional & scientific | 2019 |
| Blue Store Limited | Wholesale & retail | 2024 |
| Blue Tool Box Limited | Wholesale & retail | 2023 |
| Blue UK Building Services Limited | Construction | 2017 |
| Blue Wave Hospitality Ltd | Hospitality | 2026 |
| Blue WAX Limited | Information & communication | 2003 |
| Blue Wire Facilities Management Limited | Construction | 2025 |
| Blue Wire Fire & Security Limited | Construction | 2019 |
| Blue Wire Group Limited | Construction | 2025 |
| Blue Wire Mechanical & Electrical Ltd | Construction | 2014 |
| Blue-Collar Barbering Morley Ltd | Other services | 2026 |
| Blue-Envoy Limited | Professional & scientific | 2019 |
| Blue-Zone Housing Ltd | Real estate | 2026 |
| BLUE3 (Staffs) (Holdings) Limited | Professional & scientific | 2013 |
| BLUE3 (Staffs) Limited | Construction | 2013 |
| Blueaccess Ltd | Administrative & support | 2017 |
| Bluebank Solutions Limited | Wholesale & retail | 2007 |
| Bluebay Autos Ltd | Wholesale & retail | 2019 |
| Bluebell Court (Leeds) Management Company Limited | Households | 2005 |
| Bluebell Gallery Limited | Wholesale & retail | 2008 |
| Bluebell Mortgage and Protection Solutions Ltd | Financial services | 2019 |
| Bluebell Petite Limited | Wholesale & retail | 2024 |
| Bluebell Vision Ltd | Administrative & support | 2025 |
| Bluebell Wood Trading Company Limited | Wholesale & retail | 2004 |
| Blueberry Catering Limited | Hospitality | 2026 |
| Blueberry Events Limited | Administrative & support | 2026 |
| Blueberry Marketing Holdings Limited | Administrative & support | 2024 |
| Blueberry Marketing Solutions Limited | Administrative & support | 2005 |
| Bluebird Agents Ltd | Wholesale & retail | 2023 |
| Bluebird Inspire CIC | Agriculture & fishing | 2025 |
| Bluebird Studios Ltd | Information & communication | 2023 |
| Bluebird Vehicles Limited | Manufacturing | 2003 |
| Bluebirds Ballet School Ltd | Arts & recreation | 2010 |
| Bluebrickassociates Ltd | Real estate | 2026 |
| Bluechip Estates & Investments Limited | Financial services | 2025 |
| Bluecrest Investments Limited | Financial services | 2026 |
| Bluedogcreations Ltd | Health & social care | 2023 |
| Bluedore Limited | Information & communication | 2023 |
| Bluefin ST Marys Ltd | Hospitality | 2025 |
| Bluefinch Consultants Limited | Professional & scientific | 2019 |