| Blue Pill Records Limited | London | 2018 |
| Blue Planet Triathlon Limited | Calne | 2016 |
| Blue Plaque Productions Ltd | London | 2025 |
| Blue PM Limited | Wimbledon | 1993 |
| Blue Pro Media Limited | Northampton | 2000 |
| Blue RAE Ltd | Allithwaite | 2014 |
| Blue Ranchu Designs Limited | Glasgow | 2015 |
| Blue RAT Studios Ltd | Stockport | 2024 |
| Blue Reef (UK) Ltd | Linton | 2011 |
| Blue Rhino Investments Ltd | Thames Ditton | 2021 |
| Blue Ridge Projects Limited | Swindon | 2014 |
| Blue Rinse DOT COM Ltd | Manchester | 2017 |
| Blue Room Productions Limited | London | 2023 |
| Blue Salmon Enterprises Limited | Hertford | 2023 |
| Blue Sea Abingdon Ltd | London | 2024 |
| Blue Sea Yachting Ltd | London | 2022 |
| Blue Shark Snorkel Ltd | St. Ives | 2023 |
| Blue Sign Creation Ltd | Horley | 2025 |
| Blue Sky Arts Limited | Reading | 2001 |
| Blue Sky Connections CIC | Kington | 2024 |
| Blue Sky Flying Limited | Blackpool | 2009 |
| Blue Sky Folk Ltd | Hungerford | 2023 |
| Blue Sky Football Ltd | Derby | 2021 |
| Blue Sky Locations Limited | London | 2005 |
| Blue Sky Pilates Ltd | Musselburgh | 2007 |
| Blue Sky Sports Limited | Derby | 2019 |
| Blue Sky Symmetry Ltd | Mansfield | 2026 |
| Blue Sky Tennis Foundation CIC | Bath | 2022 |
| Blue Sky Waste Management Limited | | 2002 |
| Blue Snail Films Limited | Stonehouse | 2021 |
| Blue Space Activities Limited | Macclesfield | 2026 |
| Blue Sports & Play Ltd | London | 2021 |
| Blue Star Football Limited | Newcastle Upon Tyne | 2018 |
| Blue Star Rowing Ltd | Gateshead | 2024 |
| Blue String Music Limited | London | 2017 |
| Blue Sunflower Enterprises Ltd | London | 2012 |
| Blue Tang Swimming Ltd | Barton Upon Humber | 2017 |
| Blue Thunder Events Ltd | Ivybridge | 2020 |
| Blue Thunder Limited | Manchester | 2015 |
| Blue Thunder Sound Ltd | Ivybridge | 2020 |
| Blue Tokay Limited | Workington | 2010 |
| Blue Touch Paper Productions Limited | London | 2019 |
| Blue Town Remembered | Sheerness | 2010 |
| Blue Turtle Display Ltd | Leigh On Sea | 2023 |
| Blue Turtle Dive Charters Limited | Axminster | 2003 |
| Blue Turtle Sports Limited | Llandudno Junction | 2026 |
| Blue Uploaded Ltd | Merseyside, Southport | 2019 |
| Blue Vanilla Limited | Cheadle | 2025 |
| Blue Velvet 161 Limited | London | 2024 |
| Blue Vision Enterprise Limited | Newport | 2013 |
| Blue Voyage Ltd | Manchester | 2021 |
| Blue Wave Martial Arts Limited | Business Park Great Blakenham | 2005 |
| Blue Wave Studios Ltd | Macclesfield | 2025 |
| Blue Whale Sports UK Ltd | Manchester | 2023 |
| Blue White Sea Ltd | Hertfordshire | 2024 |
| Blue Wolf Sports Group Ltd | Whitstable | 2025 |
| Blue Yonder Books Ltd | Brigg | 2020 |
| Blue Yonder Tours Ltd | Ilfracombe | 2018 |
| Bluebay Systems Limited | Nottingham | 2010 |
| Bluebell and JOE Ltd | Stevenage | 2019 |
| Bluebell Club Limited | London | 2025 |
| Bluebell Mist Ltd | London | 2026 |
| Bluebell Productions Limited | | 2002 |
| Bluebell Railway Preservation Society | Uckfield | 2021 |
| Bluebell Wood (Cheshire) CIC | Winsford | 2022 |
| Bluebelle Designs Limited | Farnham | 2012 |
| Bluebelle Skye Productions Limited | Hornchurch | 2011 |
| Blueberry Dressage Limited | Loughborough | 2013 |
| Blueberry JAM Limited | Lancashire | 2007 |
| Blueberry Juice Ltd | Waterlooville | 2014 |
| Blueberry Media Ltd | Droitwich | 2021 |
| Bluebetty Inc Ltd | Inverurie | 2024 |
| Bluebird Eventing Limited | London | 2024 |
| Bluebird Golf Centre Ltd | Manchester | 2014 |
| Bluebird Photography Ltd | Newport | 2023 |
| Bluebird Productions Limited | Droitwich | 2022 |
| Bluebird Snowsports Limited | Calne | 2016 |
| Bluebirds Ballet School Ltd | Leeds | 2010 |
| Blueboys Coaching Limited | Colchester | 2014 |
| Bluecakes Productions Limited | Colchester | 2007 |
| Bluecoat Sports | Horsham | 2002 |
| Bluecrest Solutions Ltd | Orpington | 2024 |
| Bluedarling Limited | Rickmansworth | 2020 |
| Bluefin Holdings Limited | Market Rasen | 2018 |
| Bluefin Workshop & Events Ltd | Redhill | 2025 |
| Bluefish Live Events Limited | Walton-On-Thames | 2009 |
| Bluefox Boards Limited | Poole | 2021 |
| Bluefox Water Sports Limited | Poole | 2019 |
| Bluegrey Design Limited | Kingston Upon Thames | 2020 |
| Bluehouse Artspace Ltd | Esher | 2025 |
| Bluejam Arts CIC | Penrith | 2007 |
| Bluejays Productions Ltd | Stockport | 2020 |
| Bluekens Limited | Great Glen | 2020 |
| Bluelight Cycling Club CIC | Romford | 2021 |
| Blueline Leisure Limited | Loughborough | 2011 |
| Bluemoon Consultancy Ltd | London | 2019 |
| Blueprint Arts Foundation CIC | Gravesend | 2007 |
| Blueprint Design and Frames Ltd | Leyland | 2015 |
| Blueprint Design Company Limited(The) | Chichester | 1985 |
| Blueprint Fitness London Ltd | London | 2014 |