| C B Custom Truck Interiors Limited | Kilmarnock | 2026 |
| C B Domestics Limited | Salisbury | 2011 |
| C B Fabrications (UK) Limited | Morecambe | 2012 |
| C B K Systems Limited | Mexborough | 1991 |
| C B Leather Limited | Tunbridge Wells | 2003 |
| C B M Installations Limited | London | 1997 |
| C B Mech Limited | Hungerford | 2017 |
| C B Stone Limited | London | 2019 |
| C B Upholstery Limited | New Milton | 2012 |
| C Bannister Engineering Services Ltd | London | 2014 |
| C Barlow Fencing Limited | Leyland | 2015 |
| C Barrow Engineering Ltd | Halifax | 2022 |
| C Bradley Fabrications Limited | Bedworth | 2007 |
| C Bradley Motor Engineers Ltd | Draperstown | 2003 |
| C Brown Joinery Ltd | Gateshead | 2026 |
| C C & I Ltd | Dursley | 2005 |
| C C E Services Limited | London | 2020 |
| C C Iancu Ltd | Dagenham | 2025 |
| C C L Traditional English GUN Products Limited | Redditch | 1983 |
| C C L Vision Limited | London | 1989 |
| C C N Contractor Ltd | Newport | 2022 |
| C C Refrigeration (Midlands) Limited | Nottingham | 2013 |
| C C S Neon Limited | Leeds | 1993 |
| C C S Textile Equipment Limited | London | 2002 |
| C Cake Ltd | Bristol | 2025 |
| C Cappilli Limited | Sutton | 2023 |
| C Carnevale Limited | London | 2008 |
| C Carpentry Limited | Grimsby | 2010 |
| C Case Carpentry Limited | Barry | 2025 |
| C Centre Ltd | London | 2022 |
| C Corbett Engineering Ltd | Ilkeston | 2017 |
| C D & J Tanks Ltd | Stoke-On-Trent | 2016 |
| C D B Engineering Ltd | Wimborne | 2006 |
| C D Ball Aviation Ltd | Southport | 2018 |
| C D Equipment Engineering Limited | Pershore | 2003 |
| C D S (UK) Limited | Newport | 2011 |
| C D T Sidoli (Welshpool) Limited | Powys | 1982 |
| C D Yarn Ltd | Manchester | 2025 |
| C DON Wind Ltd | Liverpool | 2016 |
| C E E Relays Limited | Sandhurst | 1986 |
| C E G Marine Engineering Ltd. | Nairn | 2014 |
| C E J Grig Limited | Camberley | 2013 |
| C E L Leadwork Contracts Limited | Peterborough | 1991 |
| C Evans Commercial Limited | Shrewsbury | 2010 |
| C F Electronics Limited | Fareham | 2002 |
| C F International Limited | Hayling Island | 2006 |
| C F Laminators Ltd | Horndean | 2025 |
| C F Lawnmower Services Ltd | Caterham | 2021 |
| C F Mechanical Services Ltd | Wembley | 2013 |
| C Firth Group Ltd | Barnsley | 2023 |
| C Flint Services Ltd | Cardiff | 2025 |
| C Fraser Welding Services Ltd | Tain | 2025 |
| C G C Technology Limited | Salford | 1999 |
| C G Electrical Limited | Preston | 2018 |
| C G Engineering & Construction Ltd | Widnes | 2014 |
| C G Owen Engineering Limited | Sunderland | 2018 |
| C G P Welding Limited | Lockerbie | 2008 |
| C G Print Limited | Glasgow | 2002 |
| C G Wind Ltd | Blyth | 2021 |
| C GEE Services Limited | Waterlooville | 2013 |
| C Gibbon Facility Solutions Ltd | Bedlington | 2017 |
| C Globe Traders Ltd | New Malden | 2013 |
| C Groves Limited | Evesham | 2023 |
| C H Air & Pump Services Limited | Ipswich | 1995 |
| C H Autogroup Ltd | London | 2025 |
| C H Bennett and SON Limited | Powys | 2003 |
| C H Broadcast Ltd | Chessington | 2020 |
| C H M Doors Ltd | Brierley Hill | 2018 |
| C H P Services (Midlands) Limited | Dudley | 2015 |
| C H Sandall & SON Limited | Sleaford | 2000 |
| C H Steel Fabrication Limited | Workington | 2003 |
| C Hardy Electrical Ltd | Nottingham | 2023 |
| C Howe Electrical Ltd | Southampton | 2020 |
| C I Developments Limited | Exeter | 2010 |
| C I Electrical Projects Limited | Sutton Coldfield | 2013 |
| C J a Engineering Ltd | Cannock | 2024 |
| C J a Marine Services Limited | Ipswich | 2009 |
| C J Appliances Ltd | Colchester | 2015 |
| C J Autos (Heywood) Limited | Heywood | 1997 |
| C J Bradshaw Ltd | Belper | 2024 |
| C J Brooks the Jewellery Workshop Limited | Colchester | 2003 |
| C J Brownlie Contracts Ltd. | Hamilton | 2015 |
| C J Buildtech Limited | Milton Keynes | 2019 |
| C J Carpentry Services Ltd | Cwmbran | 2024 |
| C J Carpet Binding Ltd | Glasgow | 2013 |
| C J Carter Ltd | Camberley | 2015 |
| C J Clark Forestry Limited | Knaresborough | 2026 |
| C J Consulting Midlands Limited | Wolverhampton | 2019 |
| C J Conversions Limited | Lincoln | 2003 |
| C J COX Limited | Dorset | 1997 |
| C J Developments (Wirral) Limited | Wirral | 2018 |
| C J Engineering (Thetford) Limited | Norfolk | 1998 |
| C J ENT UK Ltd | Neath | 2015 |
| C J GAS Engineering Ltd. | Newport | 2013 |
| C J Hydraulic Services Limited | Hartlepool | 1994 |
| C J Keitch Engineering Limited | Honiton | 2012 |
| C J Laing Property Maintenance Ltd | Ruislip | 2019 |
| C J Marine Ltd | Peterhead | 2015 |
| C J Matthew Solutions Ltd | London | 2025 |
| C J Mckeever Services Ltd | Worcester | 2021 |