| Blue Minds Nutrition Ltd | London | 2025 |
| Blue Mission Technology Limited | Bedford | 2024 |
| Blue Monarch Ltd | Ruislip, | 2026 |
| Blue Monkey Brewing Limited | Nottingham | 2008 |
| Blue Monkey Vending Limited | Cardiff | 2014 |
| Blue Moon Car Hire & Services Ltd | Bilston | 2014 |
| Blue Moon Foods Limited | Leicester | 2002 |
| Blue Moon Hotels Procurement Services Limited | Crawley | 2014 |
| Blue Moon Paint Services Limited | Penarth | 2017 |
| Blue Moon Promotions Limited | Stockport | 1988 |
| Blue Moon Stone Ltd | London | 2024 |
| Blue Motus Ltd | Pinner | 2024 |
| Blue Mountain Coffee Group Limited | London | 2017 |
| Blue Mountain View Medical Services North East Ltd | London | 2025 |
| Blue Mushroom Digital Ltd | Ashford | 2019 |
| Blue Mushroom Limited | Surrey | 2000 |
| Blue Neptune International Ltd | London | 2025 |
| Blue Nile Desserts Limited | Manchester | 2025 |
| Blue Nival Company Limited | Stafford, | 2026 |
| Blue Notion Ltd | Stockport | 2018 |
| Blue Oak Manufacturing Limited | Milton Keynes | 2013 |
| Blue Oaks Solutions Ltd | Cambridge | 2020 |
| Blue Ocean Decom International Limited | Huntly | 2026 |
| Blue Ocean Industrial Development (UK) Limited | London | 2012 |
| Blue Ocean Robotics Limited | London | 2019 |
| Blue Ocean Studios Ltd | Leigh-On-Sea | 2022 |
| Blue Ocean Textile Ltd | Newcastle Upon Tyne | 2015 |
| Blue Olivine Ltd | York | 2025 |
| Blue Oval Creative Limited | Hull | 2008 |
| Blue Oval Limited | | 1902 |
| Blue Panda Limited | Bournemouth | 2003 |
| Blue Papaya Ltd | Coventry | 2020 |
| Blue Peacock Studio Limited | Bourne End | 2020 |
| Blue Pebble Technology Ltd | Ely | 2017 |
| Blue PEN Limited | London | 2005 |
| Blue Penny Developments Limited | Corby | 2022 |
| Blue Phoenix Group Limited | Bourne | 2017 |
| Blue Phoenix Limited | Bourne | 1996 |
| Blue Plan Design Limited | Manchester | 2022 |
| Blue Planet Buildings (UK) Limited | Nottingham | 2011 |
| Blue Planet Holdings Ltd | Trowbridge | 2023 |
| Blue Planet Solutions UK Limited | London | 2025 |
| Blue Print & Display Limited | Langham | 2013 |
| Blue Print High Wycombe Limited | Fareham | 2013 |
| Blue Print Management Services Limited | Droitwich | 1995 |
| Blue Raptor Limited | Hampshire | 2002 |
| Blue Rhino Graphix Limited | Oldham | 2020 |
| Blue Rhinoceros Company Limited | West Midlands, England | 2024 |
| Blue Ridge Shipping Limited | London, England | 2025 |
| Blue River Controls Limited | High Wycombe | 2003 |
| Blue River Group (UK) Ltd | Hull | 2009 |
| Blue River Innovations Ltd | Stevenage | 2015 |
| Blue Roll Press Community Interest Company | Bristol | 2024 |
| Blue Room Arts Limited | Braintree | 2024 |
| Blue Safe GAS Limited | London | 2023 |
| Blue Sail Technologies Ltd | Belfast | 2024 |
| Blue Screen Limited | Huddersfield | 2016 |
| Blue Shift Games Ltd | London | 2021 |
| Blue Shuck Consulting Ltd | Houghton Le Spring | 2026 |
| Blue Siren Ltd | London | 2023 |
| Blue Skies (UK) Limited | Northampton | 1997 |
| Blue Skies Fruits Limited | Northampton | 2025 |
| Blue Skies Holdings Limited | Northampton | 2000 |
| Blue Skies International Limited | Northampton | 2023 |
| Blue Sky Above Limited | London | 2025 |
| Blue Sky Alterations Ltd | Rottingdean | 2022 |
| Blue Sky Assemblies Ltd | Burnley | 2009 |
| Blue Sky Botanics Limited | Herefordshire | 2005 |
| Blue Sky Designers Ltd | London | 2008 |
| Blue Sky Engineering and Solutions Limited | Lincoln | 2017 |
| Blue Sky Engineering UK Ltd | Carmarthen | 2009 |
| Blue Sky Engines Limited | Ayr | 2012 |
| Blue Sky Enterprises Limited | Ferndale | 1997 |
| Blue Sky Event Cinemas Limited | Cowling | 2024 |
| Blue Sky Fashion Limited | Leicester | 2020 |
| Blue Sky Imaging Limited | Dorking | 1998 |
| Blue Sky Internation Trading Limited | Beckenham | 2023 |
| Blue Sky Joinery Limited | Rugby | 2013 |
| Blue Sky Kitchen Design Limited | Basingstoke | 2024 |
| Blue Sky Laser Technologies Ltd | Swansea | 2016 |
| Blue Sky Metal Fabrication Ltd | Swansea | 2019 |
| Blue Sky Music Limited | London | 2000 |
| Blue Sky Outdoor Kitchens Ltd | Reading | 2021 |
| Blue Sky Printing Services Ltd | London | 2020 |
| Blue Sky Refrigeration Limited | Lincoln | 2023 |
| Blue Skyline Engineering Limited | Surbiton | 2024 |
| Blue Smoke Meat Limited | London | 2017 |
| Blue Spark Holdings Limited | Blackburn | 2008 |
| Blue Square Brewery Limited | Leeds | 2020 |
| Blue Star Engines Limited | | 1988 |
| Blue Star Fibres Company Limited | Grimsby | 2006 |
| Blue Star FM Limited | Cannock | 2017 |
| Blue Star Glazing Limited | Pinner | 2021 |
| Blue Star Pattern Toys Ltd | Hull | 2014 |
| Blue Star Print Solutions Ltd | Northampton | 2014 |
| Blue Strand Marine Limited | Southampton | 2013 |
| Blue Streak Aviation Ltd | Wadebridge | 2025 |
| Blue Streak Europe Limited | Annesley | 1996 |
| Blue Sun AC Limited | Rugby | 2020 |
| Blue Sun International Ltd | London | 2025 |