| Blast Ituk Ltd | Birmingham | 2016 |
| Blast N Coat Limited | Wickford | 2024 |
| Blast OFF Paisley Ltd | Glasgow | 2021 |
| Blast OFF!! Services (Spalding) Ltd | Spalding | 2011 |
| Blast Power Services Limited | Diss | 1986 |
| Blasta Henriet Ltd | Richmond | 2017 |
| Blasted Limited | Barrow-Upon-Humber | 2013 |
| Blaster Hair Technologies Limited | London | 2014 |
| Blasthaus Ltd | Yarm | 2021 |
| Blastr Green Steel Limited | Watford | 2024 |
| Blasus Welshcakes Ltd | Carmarthen | 2023 |
| Blatchford Limited | Basingstoke | 1919 |
| Blatchford Products Limited | Basingstoke | 2002 |
| Blauberg UK Limited | Leicester | 1999 |
| Blave Ltd | London | 2024 |
| Blaxhairfashioin Ltd | Barnet | 2024 |
| Blaxx Ltd | Darlington | 2024 |
| Blaxy Ltd | Mildenhall | 2022 |
| Blay Carpentry Limited | London | 2025 |
| Blaydon Caravans Ltd | Blaydon On Tyne | 2012 |
| Blayson - Olefines Limited | Cambridge | 1961 |
| Blayson Casting Systems Limited | Cambridge | 1990 |
| Blayze Tech Limited | Bury St. Edmunds | 2020 |
| Blaze (UK) Thermal Technology Co., Ltd | West Midlands | 2023 |
| Blaze Maintenance Limited | Tunbridge Wells | 1983 |
| Blaze Point Heating Ltd | Woking | 2022 |
| Blaze Productions Limited | Bath | 1998 |
| Blaze Signs Limited | Broadstairs | 1980 |
| Blazebreaker Limited | London | 2024 |
| Blazed Distro Ltd | Alfreton | 2016 |
| Blazed Limited | South Shields | 2017 |
| Blazej Lesniczak Services Ltd | Bournemouth | 2025 |
| Blazeline Welding and Pipefitting Solutions Ltd | Lincoln | 2026 |
| Blazer Line Limited | Salisbury | 2010 |
| Blazers Fuels Limited | Penrith | 2013 |
| Blazers Group Limited | Penrith | 2022 |
| Blazetech Systems Ltd | Milton Keynes | 2025 |
| Blazing Limited | Bolton | 2019 |
| Blazion Ltd | Edinburgh | 2025 |
| Blazon Fabrications Limited | Gravesend | 1979 |
| Blazon Holdings Limited | Gravesend | 2008 |
| Blazon Studios Limited | Luton | 2014 |
| BLC Aviation Ltd | Leigh-On-Sea | 2024 |
| BLC Carpentry Ltd | Edgware | 2026 |
| BLC Limited | Church Stretton | 2009 |
| Blck Matter Ltd | London | 2019 |
| Blckgld Limited | Nottingham | 2020 |
| BLD Installations Limited | Birmingham | 2014 |
| BLD International Fashion Agency Limited | London | 1982 |
| BLD Technology Ltd | Manchester | 2018 |
| BLD Transit Limited | Basingstoke | 2026 |
| BLE Lighting and Power Limited | Sheffield | 1968 |
| BLE Smoke and Fire Curtains Limited | Sheffield | 2004 |
| Ble's Love Cakes Ltd | Ashford | 2025 |
| Bleakman Bodyworks Limited | Romford | 2025 |
| Bleasby Hive Limited | Romsey | 2021 |
| Bleat Post Production Ltd | London | 2021 |
| Bleed IV Records Ltd | Coventry | 2021 |
| Bleeding Beauty Boutique Ltd | Barnsley | 2022 |
| Bleeding Gums Wrestling Ltd | Kirkcaldy | 2025 |
| Bleedstoppers International Ltd | Worthing | 2021 |
| Bleeper Services Limited | Bolton | 2001 |
| Blees Gold Ltd | Romford | 2015 |
| Blekoo Ltd | Rugby | 2026 |
| Blembler & Arpviks Group Limited | Cockermouth | 2022 |
| Blemkleen (North West) Limited | Lancaster | 1984 |
| Blenco Bespoke Ltd | Leicester | 2025 |
| Blencowe’S Hospitality Limited | Banbury | 2020 |
| Blend Barbershop Ltd | Liverpool | 2023 |
| Blend Coffee Roasters UK Ltd | London | 2026 |
| Blend Southbourne Ltd | Bournemouth | 2026 |
| Blend UR Spice Ltd | Bradford | 2021 |
| Blend&Sip Ltd | London | 2026 |
| Blend'D Drinks Ltd | London | 2024 |
| Blend-I-Pack Limited | Buxton | 2000 |
| Blended Products Limited | Brigg | 2003 |
| Blended WAX Melts & More Ltd | Barnsley | 2025 |
| Blending and Bottling Solutions Limited | Birkenhead | 2014 |
| Blendings Limited | Stockton-On-Tees | 2013 |
| Blendly Ltd | London | 2016 |
| Blendmade Nutrition Ltd | Rendlesham | 2026 |
| Blendology Labs Limited | Kelso | 2025 |
| Blendology Limited | Cambridge | 2011 |
| Blends Flavours & Colours Limited | Prescot | 2017 |
| Blends for Friends Limited | Reigate | 2005 |
| Blends Holdings Limited | Prescot | 2017 |
| Blends Lifestyle Limited | Edinburgh | 2021 |
| Blends Limited | Prescot | 1998 |
| Blendtek Solutions Limited | Solihull | 2020 |
| Blendworth Interiors Limited | Darwen | 2022 |
| Blendz by Gemz Ltd | London | 2025 |
| Blendzz Scents Ltd | London | 2023 |
| Blenheim Forge Limited | Swanley | 2020 |
| Blenkinsop Leathers Limited | Northamptonshire | 1989 |
| Blenkinsopp Collieries Limited | Newcastle | 1954 |
| Blent Group Limited | Okehampton | 2025 |
| Bless Fitted Wardrobes & Kitchens Ltd | Hayes | 2025 |
| Bless Start Limited | Guildford | 2023 |
| Bless Textiles Limited | Crawley | 2026 |
| Bless'D Beneath Ltd | Mildenhall | 2025 |