| Cspc (Pharmacy) Limited | Cheltenham | 2007 |
| CSR Nexus Consulting Ltd | Luton | 2024 |
| CSS Audenshaw Limited | London | 1936 |
| CSS Locksmiths Limited | Fareham | 1970 |
| Csscreative Limited | Barnet | 2023 |
| Cssic Media Limited | Bushey | 2020 |
| Cssl NO. 2 Limited | Chipping Norton | 2021 |
| CST Hydraulics Limited | Macclesfield | 2022 |
| Cstm Limited | London | 1983 |
| Cstt Properties Limited | Market Harborough | 2021 |
| CSV Employees Trustees Ltd | Belfast | 2022 |
| CSW Controls Limited | Cwmbran | 2013 |
| CSW Property (Scotland) Ltd | Glasgow | 2016 |
| Csya Trustees Limited | Galashiels | 2020 |
| CT Dent Limited | Manchester | 2022 |
| CT Hvac Co., Ltd | Cambridge | 2018 |
| CT Investment Management Ltd | Edinburgh | 2012 |
| CT Naia Ltd | London | 2024 |
| CT Software Consultancy Ltd | York | 2018 |
| CT Trading Limited | Camberley | 2004 |
| CTC Forestry Nominee 1 Limited | London | 2012 |
| CTC Forestry Nominee 2 Limited | London | 2012 |
| CTC Invest Sweden Limited | London | 2021 |
| CTC Lawyering Limited | London | 2020 |
| CTC Publishing Ltd | Birmingham | 2023 |
| CTC Sweden Limited | London | 2021 |
| Ctcoo Ltd | London | 2024 |
| Cteot Limited | Sudbury | 2024 |
| CTH Consulting Limited | Abingdon | 2007 |
| Cthru Smiles Limited | Sheffield | 2018 |
| Cthulhu 1 Ltd | London | 2025 |
| CTL Estates Ltd | Manchester | 2002 |
| CTM Property Maintenance Ltd | Havant | 2020 |
| CTN Management Limited | Manchester | 2021 |
| CTP Alan Limited | Mitcham | 1973 |
| CTP Davall Limited | Musselburgh | 1968 |
| CTP Lichfield Limited | Mitcham | 1938 |
| CTP Manchester Limited | Sale | 2014 |
| CTP Moulded Gears Limited | Mitcham | 1963 |
| CTP Precision Tooling Limited | Mitcham | 1997 |
| CTP Silleck Limited | Mitcham | 1945 |
| CTP Silleck Scotland Limited | Musselburgh | 1992 |
| CTP White Knight Limited | Mitcham | 1971 |
| Ctps - ERP Consulting, Training & Project Services Ltd. | Dudley | 2016 |
| Ctrl-Intelligence Ltd | Newry | 2013 |
| CTS (UK) Limited | Stroud | 1996 |
| CTS Alliance Ltd | Harrogate | 2017 |
| CTS Analytical Limited | Craigavon | 1967 |
| CTS Hull Limited | Hull | 2009 |
| Ctsignage Technology Co., Ltd | Beckenham | 2014 |
| CTT Group Ltd | Tunbridge Wells | 2016 |
| Ctve-Cambridge Talent Vision Education Ltd | Beckenham | 2016 |
| CTW Recruitment Ltd | London | 2018 |
| CTY Urmston Limited | Blackpool | 2015 |
| Ctypromos Co., Limited | Beckenham | 2018 |
| CU Connected Ltd | Salisbury | 2010 |
| CU Protected Ltd | Salisbury | 2010 |
| Cuando Sailing Ltd | Harrow | 2025 |
| CUB Care Nursery Ltd | Bristol | 2019 |
| Cuba Property Limited | Salisbury | 2007 |
| Cuban Atmosphere Limited | Eastbourne | 2023 |
| Cubble Tech Ltd | Haddington | 2023 |
| Cubbon Management Ltd | Coventry | 2014 |
| Cube Basements Limited | Weybridge | 2018 |
| Cube Build Limited | Weybridge | 2011 |
| Cube Dynamic Limited | Nottingham | 2012 |
| Cube Holdings Ltd | Manchester | 2017 |
| Cube Home Energy Saving Solutions Limited | Keighley | 2023 |
| Cube Incubator Limited | Northampton | 2020 |
| Cube Records Limited | London | 2004 |
| Cubed Racing Limited | Harpenden | 2020 |
| Cubeitz Group Limited | Bournemouth | 2018 |
| Cubestores UK Ltd | Redditch | 2019 |
| Cubgap Limited | London | 2024 |
| Cubic Apple UK Limited | Atherstone | 2013 |
| Cubic Flow Ltd | Newmarket | 2025 |
| Cubic Rentals Limited | Leeds | 2021 |
| Cubicle Store Limited | Liversedge | 2019 |
| Cubis Bruton Management Company Limited | London | 2018 |
| Cubis Bruton (Acorn) Limited | London | 2020 |
| Cubist Solutions Ltd | York | 2018 |
| Cubitt & West Estate Agents Limited | Horsham | 1992 |
| Cuckoo GIN Limited | Chorley | 2017 |
| Cuckoo Trading Hebei Co., Ltd | Kington | 2021 |
| Cucumber Sweet Waves Ltd | London | 2024 |
| Cucumber There and Then Limited | Potters Bar | 2011 |
| Cudark Limited | Liskeard | 2023 |
| Cudd Bentley Holdings Limited | Ascot | 2017 |
| Cuddy Lane Ltd | Mildenhall | 2023 |
| Cudmore & Cudmore Limited | Birmingham | 2018 |
| Cudweed Management Company Limited | Small Dole | 2014 |
| Cudworth 1961 Limited | Barnsley | 2014 |
| Cuemark Limited | Slough | 2013 |
| Cufaude Company Limited | Farnborough | 2023 |
| Cuffe and Taylor Limited | London | 2016 |
| Cuffley 1960 Limited | Hemel Hempstead | 2014 |
| Cuhadar Yachting Ltd | Blackpool | 2024 |
| Culcheth Property Management Limited | Merseyside | 2007 |
| Culinarycrafters Ltd | Edinburgh | 2025 |
| Cullen Packaging Limited | Glasgow | 2009 |