| Blackswanobsidian.Media Ltd | Braintree | 2025 |
| Blackswanobsidian.Tv Ltd | Braintree | 2025 |
| Blackswarm Consortium Limited | London | 2025 |
| Blackthorn and Beech Ltd | Manchester | 2026 |
| Blackthorn Dog Co Ltd | London | 2026 |
| Blackthorn Environmental Ltd | London | 1995 |
| Blackthorn Furniture Ltd | Newry | 2012 |
| Blackthorn Industrial Supply Ltd | London | 2026 |
| Blackthorn of Kent Ltd | Potters Bar | 2024 |
| Blackthorn Spirits Company Ltd | London | 2026 |
| Blackthorn Workshop Limited | Beauchamp, Pershore, Worcester | 2003 |
| Blackthorne Specialist Joinery Ltd | Waltham Abbey | 2017 |
| Blacktick Limited | Bradford | 2003 |
| Blacktop Asphalt Ltd | Welwyn Garden City | 2025 |
| Blacktop Products Ltd | Coalisland | 2023 |
| Blacktop Restorations Ltd | Church Stretton | 2025 |
| Blacktrack Limited | N Yorkshire | 2004 |
| Blackvein Circuits Limited | Newport | 2017 |
| Blackwainer Ltd | London | 2025 |
| Blackwall Assist Ltd | London | 2026 |
| Blackwater Brewing Company Limited | Southminster | 2022 |
| Blackwater Coffee Ltd | Burnham-On-Crouch | 2024 |
| Blackwater Composites Limited | Elmstead Market | 2023 |
| Blackwater Engineering Limited | Downpatrick | 1998 |
| Blackwater Manufacturing Limited | Glenrothes | 1987 |
| Blackwater Medical Ltd | Dungannon | 2020 |
| Blackwater Photographic Company Limited | Fleet | 1974 |
| Blackwater Plastics Limited | Leigh-On-Sea | 1994 |
| Blackwater Property Investments Ltd | Braintree | 1999 |
| Blackwater Sign and Print Limited | Leigh-On-Sea | 2024 |
| Blackweed SE16 Limited | London | 2025 |
| Blackweld Limited | Tipton | 1985 |
| Blackwell and Moody Limited | Winchester | 2002 |
| Blackwell Automation Ltd | Colchester | 2018 |
| Blackwell Engineering Solutions Ltd | City | 2022 |
| Blackwell Games Ltd | Glasgow | 2025 |
| Blackwell House Clothing Ltd | Norwich | 2025 |
| Blackwell House Farm Ltd | Romford | 2026 |
| Blackwell Original Drums Limited | Ely | 2013 |
| Blackwell's Pasties Limited | Torrington | 2002 |
| Blackwells Jewellers Ltd | Gravesend | 2018 |
| Blackwood & Locke Ltd | Stroud | 2011 |
| Blackwood Blinds Limited | Luton | 2000 |
| Blackwood Chainsaws Ltd | Blackwood | 2005 |
| Blackwood Composites Ltd | Milton Keynes | 2014 |
| Blackwood Engineering Limited | Gwent | 1946 |
| Blackwood Fabrications Ltd | Coalville | 2022 |
| Blackwood Kitchens Ltd | Cheshire | 2003 |
| Blackwoods Cheese Company Ltd | Edenbridge | 2015 |
| Blacky's Kitchen Ltd | Poole | 2024 |
| Blackyard Coffee LAB. Ltd | Kirkby Stephen | 2022 |
| Bladdin Ltd | Mansfield | 2020 |
| Blade Access Services Ltd | Sunderland | 2018 |
| Blade Bikelights Limited | Enfield | 2017 |
| Blade Consultant Services Ltd | Macclesfield | 2020 |
| Blade Farming Limited | Birmingham | 2003 |
| Blade Gamer Limited | Birmingham | 2025 |
| Blade Pens Ltd | Shrewsbury | 2025 |
| Blade Protection Ltd | Romford | 2023 |
| Blade Repair Global Ltd | Newport | 2022 |
| Blade Repair Renewables Ltd | Sunderland | 2024 |
| Blade Restore Ltd | Hull | 2024 |
| Blade Rubber Craft Ltd | Crystal Palace | 2021 |
| Blade Rubber Stamps Ltd | Hebden Bridge | 2002 |
| Blade Secure Limited | North Molton | 2021 |
| Blade Sharpening UK Ltd. | Hartfield | 2026 |
| Blade Tooling Company Limited | Burnley | 2011 |
| Blade Ventures Limited | Nottingham | 2021 |
| Blade Works Ltd | Southampton | 2025 |
| Bladebest Limited | Rotherham | 1974 |
| Bladebug Limited | London | 2014 |
| Bladecoreuk Ltd | Hull | 2026 |
| Bladecutter Limited | Appleby-In-Westmorland | 2014 |
| Bladelock Door Limited | Doncaster | 2015 |
| Blades Joinery Limited | Knoll Rise | 2006 |
| Blades LOW Carbon Systems Ltd | Plymouth | 2011 |
| Blades Mowers Limited | Northwich | 2023 |
| Blades Newc Ltd | Newcastle | 2025 |
| Blades of Savile ROW Limited | | 1981 |
| Blades Ramble Ltd | Wakefield | 2023 |
| Bladestar Renewables Ltd | Darlington | 2019 |
| Bladeteam Limited | Hessle | 2023 |
| Bladetech Limited | Pontefract | 2022 |
| Bladez Toyz Limited | Marlow, | 2007 |
| Bladnoch Distillery Limited | London | 2014 |
| Bladon Jets (UK) Limited | Manchester | 2002 |
| Bladon Technologies Limited | Warwick | 2024 |
| Bladud Flies Limited | Tregaron | 2013 |
| Bladud Spring Limited | Bath | 2017 |
| Blaenavon Forgings Limited | Matlock | 2019 |
| Blaenhalen Limited | Newcastle Emlyn | 2026 |
| Blagg & Johnson Limited | Newark | 1971 |
| Blagoy Yanchev Limited | St. Albans | 2008 |
| Blainslie Firewood Company Limited | Galashiels | 2017 |
| Blair & Patterson Home Improvements Limited | Hawick | 2007 |
| Blair & Patterson Manufacturing Limited | Hawick | 2012 |
| Blair Aerospace & Helicopter Maintenance & Support Ltd | Whitchurch | 2026 |
| Blair Biomass Ltd. | Stranraer | 2012 |
| Blair E.M.R. Limited | Lancashire | 1992 |
| Blair Marshall Blade Services Ltd | Dundee | 2026 |