| Blue Light Partnership (ASP) Holdings Limited | Maidenhead | 2012 |
| Blue Light Partnership (ASP) Limited | Maidenhead | 2012 |
| Blue Light Safety Holdings Limited | Sheffield | 2018 |
| Blue Line Buildings (Holdings) Limited | Mexborough | 1996 |
| Blue Line Risk Management Ltd | Chesham | 2009 |
| Blue Lion Group Limited | Newry | 2026 |
| Blue Lionfish Consulting Limited | Hove | 2014 |
| Blue Lizard Consulting Investments Limited | Brighton | 2012 |
| Blue Llama Ltd | London | 2020 |
| Blue Lotus Capital Limited | London | 2024 |
| Blue Machinery (Scotland) Holdings Limited | Stirling | 2026 |
| Blue Mantle Investments Ltd | Dewsbury | 2025 |
| Blue Marble Environmental Group Limited | Oldham | 2025 |
| Blue Marble Micro Limited | London | 2015 |
| Blue Marble Wealth Ltd | Kilmarnock | 2022 |
| Blue Marlin Holdings Ltd | Burnham On Sea | 2023 |
| Blue Marlin Trading Ltd | London | 2015 |
| Blue MC Finance Ltd. | London | 2021 |
| Blue MC Holdings Ltd. | London | 2021 |
| Blue Merchant Limited | Glasgow | 2025 |
| Blue Mercury Bidco Limited | London | 2025 |
| Blue Mercury Midco Limited | London | 2025 |
| Blue Mercury Topco Limited | London | 2025 |
| Blue Midco Limited | Reading | 2018 |
| Blue Monde Ltd | Chichester | 2011 |
| Blue Monkey Vending (Holdings) Limited | Cardiff | 2014 |
| Blue Moon Mortgages Limited | Wellingborough | 2005 |
| Blue Moon Partnership Limited | Retford | 2021 |
| Blue Moon Photography Limited | London | 2016 |
| Blue Moon Property Claims Ltd | Belfast | 2018 |
| Blue Moon Wealth Ltd | Harlow | 2022 |
| Blue Motor Finance DD 2 Limited | Basildon | 2019 |
| Blue Motor Finance Limited | Sundridge | 1992 |
| Blue Mountain Capacity Limited | Buntingford | 2020 |
| Blue Mountain Group Ltd | Carmarthen | 2017 |
| Blue Mountain Investments Limited | London | 2025 |
| Blue Mountain Ltd | Wembley | 2025 |
| Blue Multiplier Limited | Sutton | 2020 |
| Blue Mustard Ventures Limited | Wrexham | 2026 |
| Blue Night Investments Ltd | London | 2022 |
| Blue Nile Holdings Ltd | Southampton | 2021 |
| Blue Noble Special GP I (Scotland) Limited | Edinburgh | 2026 |
| Blue Northern BLK Ltd. | London | 2024 |
| Blue Northern Lights Ltd. | London | 2023 |
| Blue Note Advisors Limited | Newtownards | 2025 |
| Blue Note Advisory Limited | Colchester | 2018 |
| Blue Note Holdings Ltd. | London | 2022 |
| Blue Oak Capital Limited | London | 2019 |
| Blue Ocean Africa Holdings Limited | London | 2017 |
| Blue Ocean Capital Ltd. | London | 2015 |
| Blue Ocean Capital Partners Ltd | London | 2021 |
| Blue Ocean Global Holdings Ltd | London | 2020 |
| Blue Ocean Independent Financial Planning Ltd | Wickford | 2019 |
| Blue Ocean Investment Co Ltd | Ipswich | 1999 |
| Blue Ocean Investment Partners Limited | London | 2017 |
| Blue Ocean Securities Limited | London | 2025 |
| Blue Ocean Solutions Ltd | Wimborne | 2022 |
| Blue One Group Limited | Sheffield | 2023 |
| Blue Options Limited | London | 2025 |
| Blue Orange Grey Limited | London | 2021 |
| Blue Orchid (ST James) Limited | London | 2019 |
| Blue Orchid Capital Ltd | Coleshill | 2023 |
| Blue Orchid Holdings Limited | London | 2017 |
| Blue Orchid International Holdings (UK) Limited | London | 2019 |
| Blue OWL GP Stakes Advantage Europe Holdings Limited | London | 2026 |
| Blue OWL Risk Management Services Limited | Cardiff | 2018 |
| Blue OX GP Limited | London | 2024 |
| Blue PAD Limited | Colindale | 2020 |
| Blue Panda Holdings Limited | Stockport | 2023 |
| Blue Panther Holdings Ltd | Walsall | 2026 |
| Blue Pastel Ltd | London | 2026 |
| Blue PEA Ltd | London | 2025 |
| Blue Peacock Holdings Ltd | Dalmain Road | 2026 |
| Blue Peak Finance Limited | Nottingham | 2024 |
| Blue Peak Group Limited | Wokingham | 2023 |
| Blue Peak Mountain Ltd | London | 2025 |
| Blue Pebble Associates Ltd | Strabane | 2023 |
| Blue Pebble Finance Limited | Poole | 2006 |
| Blue Pebble Solutions Ltd | Skipton | 2011 |
| Blue Pelican Holdings | Milton Keynes | 2023 |
| Blue Pentagon Limited | Thamesmead | 2013 |
| Blue Pepper Mortgages Ltd | Maidstone | 2020 |
| Blue Phoenix Deepwater UK Limited | London | 2025 |
| Blue PIE (UK) Limited | Birmingham | 2014 |
| Blue Planet (Group) Limited | St. Ives | 2014 |
| Blue Planet Investment Management Ltd. | Edinburgh | 1994 |
| Blue Pool Advisors Ltd | London | 2018 |
| Blue Poppy Vehicle Solutions Limited | Pill | 2013 |
| Blue Posts Capital Limited | Sevenoaks | 2025 |
| Blue Pro Ltd | Waltham Abbey | 2022 |
| Blue Property (Group) Limited | Nottingham | 2012 |
| Blue Puffin Group Ltd | Cirencester | 2022 |
| Blue Quercus Partners Ltd | London | 2026 |
| Blue Rain Corporation Limited | London | 2011 |
| Blue Realm Ventures Ltd | Dagenham | 2021 |
| Blue Riband Group Limited | London | 2024 |
| Blue Riband Limited | Dewsbury | 2021 |
| Blue Ribbon Healthcare Group Limited | Warrington | 2020 |
| Blue Ridge Consultancy Limited | Arundel | 2016 |
| Blue Ridge Exchange Limited | Cardiff | 2011 |