| C R Services (Corby) Ltd | Corby | 2013 |
| C R Shield Holdings Limited | Leicester | 2016 |
| C R Signs (Stroud) Limited | Nailsworth | 2012 |
| C R Smith Manufacturing Limited | Dunfermline | 2010 |
| C R Stanley Carpets (Plymouth) Limited | Plymouth | 2014 |
| C R Tetstall Tiling Ltd | Stourbridge | 2008 |
| C R Thermal Insulations Ltd | Wakefield | 2012 |
| C R Tools Limited | Sheffield | 2015 |
| C Relf Maintenance Ltd | Deal | 2026 |
| C Russell Stone Merchants (Yorks) Limited | Horsforth | 2009 |
| C S (Northern) Ltd | Newton Aycliffe | 2014 |
| C S a Furniture Limited | Ipswich | 2000 |
| C S Auto Clinic Ltd | High Wycombe | 2006 |
| C S Carpentry (Shropshire) Limited | Shrewsbury | 2024 |
| C S Conversions Limited | Norwich | 2012 |
| C S Eastern Controls Ltd | Glasgow | 2024 |
| C S Engineering Services Limited | Swadlincote | 1994 |
| C S James & Sons Limited | Glasgow | 2005 |
| C S Labels Limited | Wolverhampton | 1976 |
| C S Porter Limited | Southport | 2007 |
| C S Service, Repair and Maintenance Ltd | Cleckheaton | 2021 |
| C S Solar (Yorkshire) Limited | Bridlington | 2022 |
| C S Structures Limited | Stockport | 2020 |
| C Scollan Electrical Ltd | Paisley | 2024 |
| C Scott Engineering Limited | Leicester | 2024 |
| C Shenton Pointing Ltd | Oldham | 2024 |
| C Smith Carpentry & Joinery Ltd | Bradford-On-Avon | 2024 |
| C Squared - Europe Ltd | London | 2019 |
| C Squared Building Automation Limited | Stourbridge | 2010 |
| C Stevenson Engineering Ltd | Paisley | 2025 |
| C Stewart Plant & Commercials Ltd | London | 2019 |
| C T Agricultural Services Ltd | Sevenoaks | 2009 |
| C T Glass Limited. | Bradford | 2006 |
| C T Products Ltd | Bideford | 2024 |
| C T S Process Limited | Cottingham | 2012 |
| C T Systems (UK) Limited | Huddersfield | 1995 |
| C T Trailers Ltd | Attleborough | 2019 |
| C Tech Rail Services Ltd | Sheffield | 2021 |
| C U Online UK Ltd | Manchester | 2017 |
| C U UK Limited | London | 2009 |
| C Urwin Carpentry Limited | Leatherhead | 2021 |
| C Usher Refrigeration Services Ltd | St. Neots | 2023 |
| C V Engineering Ltd | Augher | 2012 |
| C V Graphics Limited | West Yorkshire | 2006 |
| C V H Fabrications Limited | Wolverhampton | 2008 |
| C V Rollers (TPP) Limited | Oswestry | 1966 |
| C V T Services Limited | Enfield | 2022 |
| C V T Vehicle Services Limited | Birmingham | 2004 |
| C Vyse Limited | Shuttington | 2018 |
| C W Carpentry and Construction Limited | Elsworth | 2022 |
| C W Corporate Communications Limited | Redditch | 1986 |
| C W D Contracts Limited | Dudley | 2013 |
| C W Electrical Contracts Ltd | Stockton On Tees | 2010 |
| C W Electrical Kingswinford Limited | Dudley | 2012 |
| C W Electrical Services (UK) Limited | Waterlooville, | 2013 |
| C W Ellis (Halesworth) Limited | Barnards Way, Lowestoft | 2008 |
| C W Finishings Limited | Bognor Regis | 2004 |
| C W Fletcher & Sons Limited | Sheffield | 1908 |
| C W Headdress Limited | Northampton | 1996 |
| C W Kirk Lawnmowers Limited | Cambridge | 2011 |
| C W Mason Ltd | Waltham Abbey | 2024 |
| C W Services Plumbing & Heating Limited | London | 2009 |
| C W Strickland & SON Ltd | York | 2002 |
| C Wilson Technical Services Limited | Stafford | 2012 |
| C&A Country Foods Ltd | Belfast | 2024 |
| C&A Embroidery and Print Ltd | Newton Aycliffe | 2019 |
| C&A House Maintenance Ltd | London | 2021 |
| C&A Injection Moulding Ltd | Polegate | 2013 |
| C&B Auto Magic Ltd | Newcastle Upon Tyne | 2024 |
| C&B Trailer Services Ltd | Maidstone | 2024 |
| C&C Cakes Ltd | Liverpool | 2022 |
| C&C Dental Laboratory Ltd | Farndon | 2024 |
| C&C Good Food Company Ltd | Stratford-Upon-Avon | 2019 |
| C&C Kitchens Cardiff Limited | Palmers Green | 2017 |
| C&C Manufacturing Limited | Burnley | 2015 |
| C&C Oakspec Ltd | Bedford | 2018 |
| C&C Paving & Fencing Supplies Limited | Barnsley | 2021 |
| C&C Precision Engineering Limited | Keighley | 2025 |
| C&C Textiles Limited | Blackburn | 2022 |
| C&C Upholstery Ltd | Cradley Heath | 2026 |
| C&Ca Construction & Building Supplies Limited | Enfield | 2025 |
| C&Cp Ltd | Mansfield | 2015 |
| C&D Foods (Driffield) Unlimited | East Yorkshire | 1992 |
| C&E Aluminium Systems Ltd | Merseyside | 2020 |
| C&E Fiber Group Ltd | Dagenham | 2025 |
| C&F Art Interior Ltd | London | 2025 |
| C&F Green Energy (UK) Limited | Belfast | 2010 |
| C&F Industrial Services Limited | Swansea | 2023 |
| C&G Doors Ltd | Milton Keynes | 2024 |
| C&G Engineering and Ventilation Ltd | Driffield | 2023 |
| C&G Engineering Ltd | Harpenden | 2020 |
| C&G Finishes Ltd | Liverpool | 2022 |
| C&G Home Improvements Ltd | Neath | 2020 |
| C&G Meat Products Ltd | Blackburn | 2019 |
| C&G Metal Spinning Limited | Askam-In-Furness | 2013 |
| C&H Designs Ltd | Gerrards Cross | 2023 |
| C&H Electrical Services Ltd | Polegate | 2021 |
| C&H Whittle Joinery Ltd | Preston | 2022 |
| C&Hcvl Limited | Worcester | 2017 |
| C&I Electrical Contractors Ltd | Cannock | 2017 |