| Complete Sports Services Limited | Braintree | 2009 |
| Complete Spray Services Limited | Peterlee | 2019 |
| Complete Steam Solutions Limited | Manchester | 2016 |
| Complete Steel Services Ltd | Preston | 2017 |
| Complete Stone Limited | Aylesbury | 2019 |
| Complete Studio Graphics Ltd | London | 2008 |
| Complete Tail Lift Solutions Ltd. | Dunmow | 2017 |
| Complete Tail Lifts Limited | Dunmow | 2019 |
| Complete Technology Ltd | Heywood | 2007 |
| Complete Tooling Services Limited | Hull | 2015 |
| Complete Tooling Solutions Limited | Rhyl | 2003 |
| Complete Towbars Ltd | Swindon | 2012 |
| Complete Ventilation Solutions Ltd | Liverpool | 2011 |
| Complete Welding Solutions Ltd | Bedford | 2019 |
| Complete Window Systems Limited | Brierley Hill | 2004 |
| Complete Worldwide Limited | London | 2006 |
| Complete-Vit Ltd | Bedford | 2022 |
| Completed Build Ltd | London | 2025 |
| Completed Works Limited | London | 2013 |
| Completely Conkers Limited | Bury | 2017 |
| Completely Cured Ltd | Newton Abbot | 2019 |
| Completely Kent Ltd | Tolleshunt Major | 2014 |
| Complex Cold Forming Limited | Wednesbury | 2008 |
| Complex Engineering Solutions Ltd | Bradford | 2023 |
| Complex Print Media Ltd | Holywood | 2020 |
| Complexatools Limited | Glossop | 1988 |
| Complexia Limited | Leeds | 2006 |
| Compliance (N.I.) Ltd | Strabane | 2020 |
| Compliance Labelling Solutions Limited | Braintree | 2000 |
| Compliance Management Limited | Stroud | 2019 |
| Compliance Pharmahub Ltd | Harrow | 2025 |
| Compliance Posters UK Ltd | Truro | 2016 |
| Compliance Switching Solutions Limited | Carrickfergus | 2025 |
| Compliant Surface Finishing Ltd | Ashford | 2021 |
| Complipharm Ltd | London | 2025 |
| Compo Closet Ltd | Poole | 2021 |
| Compocity Ltd | London | 2023 |
| Component Coating and Repair Services Limited | Newbury | 1994 |
| Component Creations Limited | Milton Keynes | 2013 |
| Component Developments Limited | Telford | 2000 |
| Component Solutions for Industry Limited | Thetford | 1999 |
| Component Solutions Manufacturing Ltd | Chelmsford | 2023 |
| Component Supplies Limited | West Midlands | 1986 |
| Componentboard Ltd | London | 2024 |
| Components Automotives 73 Limited | Slough | 1973 |
| Compoost Toilets Ltd | Stratford-Upon-Avon | 2019 |
| Composite Air Management Limited | Stourbridge | 2017 |
| Composite BAT Ltd | Leatherhead | 2026 |
| Composite Boatworks Limited | Winchester | 2019 |
| Composite Braiding Limited | Nottingham | 2016 |
| Composite Car Company Ltd | London | 2026 |
| Composite Care Ltd | Ilford | 2025 |
| Composite Colour Ltd | Huddersfield | 2021 |
| Composite Concepts Ltd | Rochester | 2012 |
| Composite Craft Limited | Cowes | 2003 |
| Composite Craftwork Ltd | Cardiff | 2019 |
| Composite Cylinders UK Limited | Hereford | 2024 |
| Composite Designers Ltd | Cambridge | 2019 |
| Composite Direct Limited | Dewsbury | 2019 |
| Composite Door Group Limited | Renfrew | 2020 |
| Composite Doors (NW) Ltd | Wallasey | 2022 |
| Composite Doors 2 U Ltd | Hartlepool | 2015 |
| Composite Doors Ltd | Manchester | 2024 |
| Composite Dynamics Ltd | Newtownards | 2019 |
| Composite Engineering Dietrich Ltd | Cambridge | 2024 |
| Composite Integration Ltd | Saltash | 2002 |
| Composite Machining Services Ltd | Hitchin | 2015 |
| Composite Manufacturing and Design Ltd | Slough | 2010 |
| Composite Mast Engineering and Technology Limited | Bacup | 2005 |
| Composite Mech Ltd | Porthcawl | 2025 |
| Composite Poles Limited | Buckfastleigh | 2026 |
| Composite Products Limited | Chatteris | 2012 |
| Composite Projects and Resources Limited | Ayr | 2014 |
| Composite Projects Limited | Norwich | 2015 |
| Composite Refinishing Ltd | Huntingdon | 2024 |
| Composite Resin Developments Limited | Ramsgate | 2007 |
| Composite Robotics Ltd | Havant | 2018 |
| Composite Solutions UK Limited | North Shields | 2001 |
| Composite Specialities Limited | Southampton | 2024 |
| Composite Tech Holdings Limited | Orpington | 2017 |
| Composite Tooling & Engineering Solutions Ltd | Matlock | 2013 |
| Composite Tooling & Structures Ltd | Cambridge | 2018 |
| Composite Trade UK Ltd | Ilford | 2011 |
| Composites and Bifolds Ltd | High Wycombe | 2012 |
| Composites ARG Ltd | Cambridge | 2023 |
| Composites Creator Limited | London | 2025 |
| Composites Evolution Limited | Lincoln | 2009 |
| Composites TR Limited | Ferndown | 2024 |
| Composition Spirits Company Ltd | London | 2018 |
| Composs Fruit and VEG Limited | London | 2013 |
| Compossible Umwelten Ltd | Cambridge | 2026 |
| Compost Technology Limited | Shildon | 1995 |
| Compotex Limited | Rochdale | 1994 |
| Compotium Limited | Kington | 2024 |
| Compound Feed Engineering Limited | London | 1998 |
| Compound Footwear Ltd | Bath | 2022 |
| Compound Hound Ltd | Birmingham | 2023 |
| Compound Photonics UK Limited | London | 2013 |
| Compound Semiconductor Centre Limited | Cardiff | 2014 |
| Compound Solutions Ltd | Glossop | 2006 |