| Byte Cove Ltd | London | 2026 |
| Byte IT Computers Ltd | Sheffield | 2016 |
| Byte of Orange With Bits Limited | Nottingham | 2021 |
| Byte Software Ltd | Hull | 2021 |
| Byte Technology Limited | Solihull | 2013 |
| Bytebuy Electronics Ltd | Cardiff | 2025 |
| Bytec Embedded Limited | Pulborough | 1939 |
| Bytec Healthcare Limited | Pulborough | 2014 |
| Bytec Systems Limited | Pulborough | 1994 |
| Byteon Ltd | Hayes | 2015 |
| Byteops Ltd | Manchester | 2024 |
| Bythestarz Ltd | Cheltenham | 2025 |
| Bytnar-Plastic Ltd | Ashford | 2020 |
| Bytronic Automation Limited | Bromsgrove | 1997 |
| Bytronic Educational Technology Limited | Walsall | 2023 |
| Bytronic Limited | Walsall | 2023 |
| Bywater Marine Ltd | Grange-Over-Sands | 2026 |
| Bywater Property Solutions Limited | King'S Lynn | 2025 |
| Byway Craft Co Ltd | Beverley | 2025 |
| Byways Fashion Co., Limited | London | 2023 |
| Byways Limited | Watford | 1988 |
| Bywell Springs and Pressings Limited | Tipton | 1991 |
| Byworth Boilers Ltd | Keighley | 2010 |
| Byxa Limited | Harrogate | 2023 |
| Byyasmarie Ltd | London | 2021 |
| Byzanti Drinks Limited | Gerrards Cross | 2024 |
| BZ Tecnico Limited | Horsham | 2025 |
| BZH International Ltd | Solihull | 2024 |
| Bzzwax & Co. Ltd | London | 2021 |
| Bàtūrè Limited | Welling | 2020 |
| Bábá NLÁ Ltd | London | 2026 |
| BÄR Labs Ltd | London | 2026 |
| Bénir Clothing Ltd | Whetstone | 2018 |
| Bühler UK Limited | | 1947 |
| C & a Evans Limited | Newton Abbot | 2022 |
| C & a Agricultural Engineering Limited | Bishop Auckland | 2007 |
| C & a Fabrication Services Ltd | Abertillery | 2020 |
| C & a G Trans Ltd | Spalding | 2021 |
| C & a Precision Engineering Limited | Bradford | 2003 |
| C & a Tickner Limited | Cranleigh | 2006 |
| C & B Aviation Limited | Porthcawl | 2014 |
| C & B Fire Solutions Limited | Nottingham | 2022 |
| C & C Aero Ltd | Twinbrook | 2019 |
| C & C Autotech Mobile Limited | Bedford | 2024 |
| C & C Bros Ltd | Telford | 2012 |
| C & C Cabinet Makers Limited | Guildford | 2003 |
| C & C Catering Engineers Limited | London | 1998 |
| C & C Catering Fabrications Limited | London | 2015 |
| C & C Fabrications Limited | Ferrybridge | 2003 |
| C & C Fibreglass Ltd | Lincoln | 2014 |
| C & C Industrial Group Limited | Fareham | 2010 |
| C & C Living Co. Ltd | Liverpool | 2021 |
| C & C Machine Services Ltd | Northampton | 2017 |
| C & C Machining Limited | Bolton | 2019 |
| C & C Maintenance Ltd | Milton Keynes | 2011 |
| C & C Mitres Limited | Gillingham | 2002 |
| C & C Mobile Caravan Services and Sales Ltd | King'S Lynn | 2025 |
| C & C Pet Cages Limited | Bury St Edmunds | 2020 |
| C & C Precision Engineering Services Limited | Stourbridge | 2011 |
| C & C Printers Limited | Bedford | 2002 |
| C & C Sheet Metal Limited | Norwich | 2007 |
| C & C Signs Limited | Southampton | 2013 |
| C & C Site Services (UK) Limited | Essex | 1998 |
| C & C Systems Limited | Reading | 1996 |
| C & C Wales Electrical Solutions Ltd | Deganwy | 2013 |
| C & D (Microservices) Limited | London | 2003 |
| C & D (Sheet Metal) Engineering Limited | Station Road North, Belvedere, Kent | 1982 |
| C & D Associates (2008) Ltd. | Keighley | 2008 |
| C & D Body Fabrications Limited | New Romney | 2019 |
| C & D Carpentry Kent Ltd | Margate | 2018 |
| C & D Creative Engineering Ltd | Cardiff | 2015 |
| C & D Dennis Limited | Colchester | 2022 |
| C & D Designs Limited | Wilmslow | 2002 |
| C & D Electrical Plus Limited | Plymouth | 2012 |
| C & D Fabrication Limited | Chesterfield | 2003 |
| C & D Foods (Larkshall) Unlimited | Thetford | 1999 |
| C & D Hydraulics Limited | Derby | 2002 |
| C & D King Limited | Dorking | 1983 |
| C & D Limited | Wallington | 1984 |
| C & D Metalworks (UK) Limited | London | 2001 |
| C & D Print Media Limited | London | 2015 |
| C & E Limited | Doncaster | 2005 |
| C & E Nelson Limited | Kendal | 2021 |
| C & E Plating Limited | Birmingham | 1976 |
| C & F ENG Limited | Letchworth Garden City | 2016 |
| C & F Millier Limited | London | 1962 |
| C & F Turbine Services Limited | Manchester | 2010 |
| C & F Woodworks Ltd | Stirling | 2019 |
| C & G Fabrication and Welding Ltd | Sunderland | 2024 |
| C & G Fabrications Ltd | Nottingham | 2015 |
| C & G Hydraulic Services Limited | Newark | 2014 |
| C & G Joinery Limited | Wantage | 2004 |
| C & G Mowers (Lichfield) Ltd | Lichfield | 2021 |
| C & G Sharp Fabricators Limited | Lauder | 2011 |
| C & H Catto Ltd | Turriff | 2023 |
| C & H Dental Laboratory Ltd | Newport | 2025 |
| C & H Electrical | Carrickfergus | 2013 |
| C & H Electrical Services (Antrim) Limited | Carrickfergus | 2023 |
| C & H Fabrication Ltd | Durham | 2024 |
| C & H Geatches Ltd. | Devon | 2003 |