| Cerrapini Limited | Ramsgate | 2012 |
| Cerrebus Engineering Limited | Leeds | 2016 |
| Cerrig Granite & Slate Limited | Pwllheli | 2010 |
| Cerro Extruded Metals Limited | Manchester | 1998 |
| Cerseigift Ltd | London | 2023 |
| Cert Group Ltd | London | 2023 |
| Cert'N'Fase Limited | Leamington Spa | 2007 |
| CERT3GLOBAL UK Ltd | London | 2023 |
| Certa Group Service Ltd | Hemel Hempstead | 2019 |
| Certa Precision Engineering Limited | London | 2014 |
| Certa Support Services Limited | London | 2021 |
| Certa-Nutrition Ltd | Sheffield | 2025 |
| Certaim Limited | Croydon | 1984 |
| Certain Exhibitions Limited | Manchester | 2008 |
| Certain X Limited | Watlington | 2015 |
| Certatus Limited | Cardiff | 2013 |
| Certex Lifting Limited | Doncaster | 2004 |
| Certi Jewellers Ltd | London | 2025 |
| Certi Jewlz Limited | London | 2025 |
| Certified Collective Ltd | London | 2017 |
| Certified EX Solutions Limited | Deeside | 2014 |
| Certified Fire Doors and Exits Limited | Stockport | 2026 |
| Certified Foam Solutions Ltd | Romford | 2025 |
| Certified Health Ltd | Huddersfield | 2020 |
| Certified Plates Ltd | Tamworth | 2025 |
| Certified Roots Ltd | London | 2019 |
| Certified Security Solutions Ltd | Loughborough | 2021 |
| Certified State Limited | Oldham | 2017 |
| Certified Truck Solutions Ltd | Tamworth | 2025 |
| Certified-Pep Ltd | London | 2025 |
| Certifiedproinstalls Ltd | Birmingham | 2012 |
| Certitek Limited | Glasgow | 2021 |
| Certivantage Alliance Ltd | Beckenham | 2025 |
| Certivo Compliance Services Limited | Evesham | 2025 |
| Certivus Ltd | Pontefract | 2025 |
| Certo Aerospace Technologies Limited | Frome | 2007 |
| Certo Limited | Ross On Wye | 1999 |
| Certon Limited | Hemel Hempstead | 2017 |
| Certs Assured Limited | St. Albans | 2012 |
| Certs Assured Technology Limited | Swanley | 2015 |
| Certus Card Group Ltd | Skelmersdale | 1979 |
| Certus Print & Packaging Group Ltd | London | 2022 |
| Certuss (UK) Limited | Birmingham | 1989 |
| Certuss Mechanical Services Limited | Birmingham | 1972 |
| Cerulean Powerboats Limited | Ascot | 2021 |
| Cerve Limited | Lewes | 2007 |
| CES Bristol Limited | Swansea | 1982 |
| CES Cube Ltd | Faversham | 2022 |
| CES Global Ltd | Poole | 2024 |
| CES Power Ltd | Poole | 2024 |
| CES Security Solutions Ltd | Ashford | 2009 |
| CES Ventilation Hygiene Limited | Peterborough | 2015 |
| CES Welding Limited | Ellesmere | 2020 |
| CES Whisky Limited | Glasgow | 1991 |
| Cesab Limited | Wellingborough | 1990 |
| Cesare Robotics Limited | Peterborough | 2015 |
| Cesc Limited | Falmouth | 2022 |
| Cesl Hillington Limited | Glasgow | 2013 |
| Cesscon Fabrication Ltd | Livingston | 2019 |
| Cest Tout Ltd | Leicester | 2024 |
| Cestradent Limited | Ashby-De-La-Zouch | 1966 |
| Cestrian Signs Limited | Chester | 1997 |
| Cesuk Ltd | Rotherham | 2022 |
| Cesur Meat Limited | London | 2017 |
| Cesyg Ltd | Cambridge | 2019 |
| CET Limited | Loughborough | 2000 |
| Cetana Ltd | London | 2025 |
| Cetax Engineering Limited | Merseyside | 1987 |
| Cetec Europe Limited | Derby | 2010 |
| Cetfil 1 Limited | Leicester | 1996 |
| Cetin Mobile Hardware & Software Services Ltd | London | 2021 |
| Ceto Engineering Limited | St Neots | 1986 |
| Ceto Marine Ltd | Bournemouth | 2024 |
| Ceton Ltd | Huntingdon | 2025 |
| Cetronic Power Solutions Limited | Swindon | 2002 |
| Cetting Ltd | Gravesend | 2025 |
| Cetus Holdings Limited | Itchenor | 2017 |
| Cetus Powercraft Limited | Chatham Maritime | 2017 |
| Ceutica Limited | Swindon | 2021 |
| Cevizor Ltd | Nottingham | 2024 |
| Cewe Limited | Warwick | 1950 |
| Cewe Pharma Ltd | Glasgow | 2021 |
| Cexm Ltd | Devizes | 2009 |
| Cexros Ltd | London | 2025 |
| CEY Synergy Ltd | Gloucester | 2024 |
| Ceyhan Recovery (UK) Limited | Enfield | 2013 |
| Ceyket Fashion Ltd | Braintree | 2021 |
| Ceylex UK Ltd | Cardiff | 2018 |
| Ceylon Chocolate Limited | London | 2025 |
| Ceylon Drops Limited | Watford | 2026 |
| Ceylon Hub Ltd | London | 2025 |
| Ceylon Natural Vivid Sapphires Ltd | Pontefract | 2025 |
| Ceylon Organics Limited | Nottingham | 2022 |
| Ceylon Palm Ltd | Canterbury | 2025 |
| Ceylon Rani Ltd | Hayes | 2025 |
| Ceylon Tea Company Ltd | London | 2023 |
| Ceylon Tea Market Limited | Harrow | 2024 |
| Ceylona Ltd | Witney | 2025 |
| Ceylone Sanda Entertainments Ltd | Stoke-On-Trent | 2025 |
| Ceylonegy UK [PVT] Ltd | London | 2024 |