| B a T (2000) Limited | Cleckheaton | 2021 |
| B a Transmissions Limited | Keighley | 2013 |
| B Aero Ltd | Windsor | 2025 |
| B and a Precision Engineering Limited | Lancashire | 2006 |
| B and B Electrical Contractors Ltd | Newcastle Under Lyme | 2003 |
| B and C Fittings Limited | London | 2018 |
| B and D Manpower Limited | Brigg | 2014 |
| B and H Plastics Limited | Nottingham | 1987 |
| B and I Kitchen Installations Ltd | Derby | 2022 |
| B and R Builders Ltd | Stoke-On-Trent | 2026 |
| B Animal Feeds Limited | Goole | 2017 |
| B Art and Trade Ltd | London | 2019 |
| B B a K Control Panels Limited | Bedford | 1998 |
| B B Engineering (NW) Limited | Flint | 2023 |
| B B F S Blaydon Biomass Fuel Supplies Ltd | Darlington | 2024 |
| B B H Hydraulics Limited | Milton Keynes | 2003 |
| B B Plastics Ltd. | Weymouth | 2008 |
| B B Trade Kitchens & Bedrooms Limited | Houghton Le Spring | 1989 |
| B Bespoke Wardrobes Limited | Chatham | 2025 |
| B Bliss Jewellery Ltd. | Clevedon | 2025 |
| B Brackets Ltd | Swindon | 2025 |
| B Bridges Ltd | Westerham | 2023 |
| B C Agri Services Ltd | Sleaford | 2022 |
| B C Barton International Limited | Bilston | 2013 |
| B C Building and Carpentry Ltd | Portsmouth | 2022 |
| B C D Cold Rolled Strip Limited | Kingswinford | 1973 |
| B C Fabrications Limited | Wolverhampton | 2003 |
| B C Technical Services Ltd | Wells | 2014 |
| B Childs Welding & Fabrication Ltd | Newport | 2022 |
| B Chocolates (Suffolk) Ltd | Woodbridge | 2016 |
| B Connell Engineering Ltd | Newry | 2018 |
| B Creations Ltd | Gloucester | 2020 |
| B D & H Limited | Norwich | 1997 |
| B D Carpentry & Joinery Limited | Leighton Buzzard | 2021 |
| B D Customs Limited | Nottingham | 2018 |
| B D Garments Ltd | Belfast | 2023 |
| B D Gaskets & Seals Limited | Alcester | 2011 |
| B D S Electrical Limited | Newmarket | 2003 |
| B Deakin Composites Ltd | London | 2021 |
| B Delicious Ltd | Bedford | 2025 |
| B Dental Engineering Ltd | Mildenhall | 2024 |
| B Dodd Ltd | Sunderland | 2026 |
| B E Fosker Electrical Contractors Ltd | Clacton-On-Sea | 2008 |
| B E S Electrical Contractors Ltd | | 2002 |
| B E Wedge Limited | West Midlands | 2003 |
| B Electrical London Ltd | Swanley | 2020 |
| B Fluid Group Limited | Southampton | 2022 |
| B for Balo Limited | London | 2024 |
| B G a Quality Butchers Ltd | Wick | 2014 |
| B G Engineering Services Limited | Louth | 2015 |
| B G Engineers Limited | Cardiff | 2017 |
| B G Machining Ltd | Slough | 2016 |
| B G Vent Limited | Inverkeithing | 2000 |
| B G Welding & Fabrication Ltd | Preston | 2016 |
| B G Zakuska Limited | Chigwell | 2012 |
| B Griff UK Limited | Cleckheaton | 2019 |
| B H F Graphics Limited | Dartford | 2008 |
| B Hamilton Fabrication Ltd | Cowdenbeath | 2025 |
| B Heritage Auto Services Limited | Peterborough | 2025 |
| B Hogg Mechanical Services Limited | Aberdeen | 2025 |
| B Holistic Ltd | London | 2024 |
| B Holland & Sons Limited | | 2000 |
| B Holland Fabrication Services Limited | Cardiff | 2013 |
| B Holman Ltd | Southport | 2024 |
| B I Communications Limited | Essex | 1983 |
| B I Process Limited | Burton On Trent | 1986 |
| B I Technology Essex Limited | Basildon | 2010 |
| B IS for Buff Ltd | Bridgend | 2025 |
| B J Building Services North East Limited | Gateshead | 2025 |
| B J C Gold Ltd | London | 2020 |
| B J Chant & Sons Limited | London | 1997 |
| B J Fencing Supplies Limited | Cannock | 2021 |
| B J G Services (Derby) Limited | Derby | 2003 |
| B J M Design Limited | Hamilton | 2017 |
| B J S Company Limited | Greenford | 1945 |
| B J Williamson Ltd | Whalsay | 2023 |
| B J Wood and SON Limited | East Sussex | 2007 |
| B J'S Fast Food Supplies Limited | Lisburn | 1999 |
| B Jardine Engineering Ltd | Aughnacloy | 2018 |
| B K Blinds and Shutters York Ltd | Huddersfield | 2022 |
| B K F Designs Limited | Brackley | 2009 |
| B K Home Improvements Ltd | Coventry | 2025 |
| B K Refregiration Ltd | Fareham | 2025 |
| B K Sheet Metal Limited | Sutton Coldfield | 2010 |
| B K Wright Ltd | Eastleigh | 2019 |
| B Knight & SON Limited | Lincoln | 2003 |
| B L & Sons Carpentry Ltd | Gainsborough | 2021 |
| B L C Fabrications Ltd | Cheltenham | 2001 |
| B L H Realisations Limited | Birmingham | 1901 |
| B L Hopkinson Constructional Engineering Limited | Uttoxeter | 1999 |
| B L Shutters Limited | Co Armagh | 2002 |
| B L Welding and Fabrications Ltd | Harrogate | 2020 |
| B Levy & Co,(Patterns)Limited | Chigwell | 1949 |
| B Lifting UK Ltd | London | 2026 |
| B Line Electrical Ltd | Bristol | 2024 |
| B Line Rapid Response Ltd | Sunderland | 2026 |
| B Lite Electrical Ltd | West Bromwich | 2025 |
| B Loves Co Limited | Belfast | 2025 |
| B M Agri. Engineering Ltd | Worcester | 2022 |
| B M C Controls Limited | Greet, Winchcombe | 2001 |