| Claire Carter Limited | Administrative & support | 2016 |
| Clarity Quest Learning and Development Ltd | Professional & scientific | 2009 |
| Clarkson and Woods Holdings Limited | Professional & scientific | 2008 |
| Clean Deeper Solutions Limited | Administrative & support | 2010 |
| Clean Tech People Limited | Professional & scientific | 2009 |
| Cleaning Enterprise Limited | Administrative & support | 2003 |
| Cleantech Impact Partners Ltd | Professional & scientific | 2025 |
| Clear Support Ltd | Information & communication | 2025 |
| Cleddon Properties Limited | Real estate | 2003 |
| Cliffords Garage Ltd | Wholesale & retail | 2023 |
| Cloverlea Limited | Financial services | 2023 |
| CM Partners Limited | Professional & scientific | 2004 |
| CMS Property 2020 Ltd | Real estate | 2020 |
| CMW Supply Chain Consultancy Limited | Professional & scientific | 2024 |
| Cobden Farms Limited | Administrative & support | 2014 |
| Cogmos Limited | Professional & scientific | 2025 |
| Coils Tubes Ltd | Professional & scientific | 2022 |
| Cold Spring Consultancy Limited | Professional & scientific | 2012 |
| Colinshays Manor Limited | Real estate | 1985 |
| Collective Law Limited | Extraterritorial | 1989 |
| Commsplus Equipment Finance Limited | Administrative & support | 2013 |
| Comprendata Limited | Administrative & support | 2011 |
| Conella Ltd | Health & social care | 2013 |
| Conybeare Cottages Ltd | Hospitality | 2022 |
| Cook Bazan Properties Limited | Real estate | 2024 |
| Coombe House Enterprises Limited | Professional & scientific | 2023 |
| Coomzy Contracting Ltd | Information & communication | 2020 |
| Copernicus Services Ltd | Professional & scientific | 2018 |
| Copper Beech Holdings (Bristol) Limited | Financial services | 2025 |
| Corries Cross Ltd | Real estate | 2007 |
| Cosmic Oak Media Ltd | Arts & recreation | 2023 |
| Costa Norte Limited | Professional & scientific | 2023 |
| Costigans Limited | Hospitality | 2020 |
| Courtyard Hair Studio Ltd | Other services | 2012 |
| Cove Attractions Ltd | Administrative & support | 2017 |
| Cove Group Ltd | Information & communication | 2014 |
| Cove Heritage Properties Ltd | Construction | 2024 |
| Cove Properties Peterhead Ltd | Construction | 2025 |
| Cowling Bros Limited | Agriculture & fishing | 2015 |
| Coxley Auto Repairs Limited | Manufacturing | 2009 |
| Coxley Developments Limited | Construction | 1995 |
| Cozy Retreats Ltd | Real estate | 2023 |
| CPM Brokerage Ltd | Wholesale & retail | 2020 |
| CPS Construction Services (Holdings) Limited | Financial services | 2020 |
| Crabb Design and Building Contractors Limited | Construction | 2010 |
| Cramer (UK) Limited | Wholesale & retail | 2004 |
| Cranbourne Consulting Limited | Real estate | 2012 |
| Creating Calm Limited | Education | 2018 |
| Creative Carpets & Floors Ltd | Wholesale & retail | 2007 |
| Creative Minds Consulting Limited | Professional & scientific | 2016 |
| Creighton Associates (London) Limited | Professional & scientific | 2013 |
| Crescent FM Limited | Professional & scientific | 2018 |
| Crewelist Limited | Information & communication | 2020 |
| Croscombe Roofing Ltd | Construction | 2014 |
| Crossfit Wells Ltd | Arts & recreation | 2025 |
| Crown Glastonbury Ltd | Hospitality | 2020 |
| Custom Camera Designs Limited | Professional & scientific | 2022 |
| Custom Cameras Limited | Manufacturing | 1990 |
| Cutting Edge Events Holding Limited | Financial services | 2024 |
| Cutting Edge Events Limited | Hospitality | 2001 |
| CV Elite Limited | Administrative & support | 2011 |
| CWS IT Services Ltd | Information & communication | 2016 |
| Cypher Solutions Limited | Information & communication | 2024 |
| D & G Digital Ltd | Information & communication | 2015 |
| D & N Transport (WSM) Ltd | Transport & logistics | 2018 |
| D J Simpson Engineering Limited | Wholesale & retail | 2003 |
| D'Amore Properties Ltd | Real estate | 1997 |
| DAN Humphries Stained Glass Ltd | Administrative & support | 2015 |
| Danzo Development Limited | Professional & scientific | 2004 |
| Darby Brothers (Burrow Hill) Limited | Agriculture & fishing | 1997 |
| Darkest Avalon Limited | Information & communication | 2003 |
| Databoratory Limited | Information & communication | 2023 |
| Dave Chard Potatoes Limited | Wholesale & retail | 2005 |
| Dave Cray Consulting Ltd | Professional & scientific | 2025 |
| David Richmond Consultancy Limited | Professional & scientific | 2018 |
| Davies & Way Limited | Real estate | 2005 |
| Davis Agricultural Contracting Ltd | Agriculture & fishing | 2013 |
| DB + Paul Limited | Professional & scientific | 2014 |
| DCM Carpets & Flooring Ltd | Wholesale & retail | 2017 |
| Ddee Consulting UK Limited | Professional & scientific | 2017 |
| DDP Connects UK CIC | Education | 2017 |
| DEAN0THOMPSON Ltd | Administrative & support | 2014 |
| Delphic Holdings Limited. | Real estate | 1953 |
| Delphic Properties Limited | Real estate | 1963 |
| Desighn Limited | Extraterritorial | 2009 |
| Design & Craft Ltd | Professional & scientific | 2019 |
| Designasmiles Ltd | Health & social care | 2024 |
| Dhomer Travel Limited | Transport & logistics | 2011 |
| Dietx Services Limited | Health & social care | 2015 |
| Digimal Ltd | Wholesale & retail | 2017 |
| Dinder Drainage Management Company Limited | Households | 2025 |
| Dindersgate Farming Ltd | Wholesale & retail | 2024 |
| Dionysian Ltd | Arts & recreation | 2021 |
| Direct Catering Products Limited | Wholesale & retail | 2004 |
| Dirty Design Holdings Limited | Financial services | 2022 |
| Dirty Design Limited | Professional & scientific | 2003 |
| DM Barber Limited | Professional & scientific | 2005 |
| Dock 93 Limited | Professional & scientific | 2004 |
| Doctor Digital Consultancy Ltd | Wholesale & retail | 2024 |
| Dodxact Limited | Professional & scientific | 2017 |