| Cambridge Printing Solutions Holdings Limited | Manufacturing | 2017 |
| Cape Security Limited | Administrative & support | 2018 |
| Cardcore TCG Ltd | Wholesale & retail | 2025 |
| Cardioba Ltd | Health & social care | 2021 |
| Care Resolve Limited | Administrative & support | 2012 |
| Caresheild Ltd | Health & social care | 2018 |
| Carmaggeddon Salvage Limited | Wholesale & retail | 2017 |
| Carver Design Limited | Real estate | 2006 |
| Cast HR Solutions Limited | Other services | 2025 |
| Casual PUB & Restaurants Ltd | Manufacturing | 2024 |
| Caulfields Retail Ltd | Wholesale & retail | 2018 |
| CCP Recruitment Limited | Administrative & support | 2019 |
| Ceat Limited | Professional & scientific | 2019 |
| Censhership Limited | Professional & scientific | 2024 |
| Central Coast Pubs Ltd | Hospitality | 2023 |
| Central Surgery Limited | Health & social care | 2017 |
| Centurion Management Romford Limited | Households | 2005 |
| CGC Services Limited | Transport & logistics | 2016 |
| Champion Builders Limited | Construction | 1998 |
| Changing Times Ltd | Professional & scientific | 2019 |
| Chapel Estates Group Limited | Real estate | 2024 |
| Chariots for Hire Ltd | Transport & logistics | 2024 |
| Chez Bill Limited | Wholesale & retail | 2010 |
| Choice Physio Limited | Health & social care | 2018 |
| Choice Rentals Limited | Real estate | 2021 |
| Chris Bruce Consulting Ltd | Professional & scientific | 2021 |
| Civil Wise Limited | Construction | 2017 |
| Civisearch Ltd | Administrative & support | 2025 |
| Cj-Vend Limited | Hospitality | 2019 |
| CJD Engineering Limited | Construction | 2019 |
| CKD Estates Ltd | Households | 2025 |
| CL Remote Sales Ltd | Other services | 2025 |
| Clanwell Ltd | Construction | 2007 |
| Clean Sheep Ltd | Administrative & support | 2023 |
| Cloud Nine Pilates Ltd | Arts & recreation | 2023 |
| Cloudsto Electronics Limited | Wholesale & retail | 2012 |
| Clube 23 Company UK Limited | Information & communication | 2016 |
| Coborn Mews Management Company Limited | Households | 1986 |
| Colin Bullot & Sons Limited | Construction | 1985 |
| Color-Board Limited | Manufacturing | 1958 |
| Commac Solutions Limited | Construction | 2014 |
| Commercial Doors Limited | Construction | 2007 |
| Commercial Ladders Ltd | Wholesale & retail | 2017 |
| Common Sense Energy Limited | Other services | 2014 |
| Community Arts Lettings & Maintenance (Calm Lettings) Limited | Real estate | 2014 |
| Connect 4 Recruitment Limited | Administrative & support | 2006 |
| Conscious Living Holding Company Limited | Financial services | 2024 |
| Contractus Limited | Professional & scientific | 2016 |
| Coppertop Media Ltd | Professional & scientific | 2018 |
| Cops Plumbing Ltd | Construction | 2013 |
| Cowie Construction [Sawbridgeworth] Ltd | Construction | 2010 |
| Cowley PUB Co Ltd | Hospitality | 2018 |
| CPC Web Limited | Professional & scientific | 2013 |
| CPW Aviation Limited | Education | 2023 |
| Craven Cars Limited | Wholesale & retail | 2015 |
| CRD Electrical Services Limited | Construction | 2025 |
| Create-A-Room Ltd | Construction | 2017 |
| Creative Lime Limited | Professional & scientific | 2011 |
| Crinklebottom Limited | Extraterritorial | 2026 |
| CRM Stagg Consultancy Limited | Professional & scientific | 2011 |
| Crump & Krokos Properties Ltd | Households | 2022 |
| CS Commercial Products Limited | Wholesale & retail | 2012 |
| CT Foods Limited | Hospitality | 2025 |
| CT Shop Limited | Hospitality | 2017 |
| Curry House (S/W) Limited | Hospitality | 2022 |
| Curtis Creations Ltd | Arts & recreation | 2019 |
| Cutting Edge Printing Ltd | Manufacturing | 2017 |
| CX Systems Ltd | Information & communication | 2013 |
| Cybotech Europe Limited | Manufacturing | 2026 |
| D & M Underpinning (SE) Ltd | Construction | 2006 |
| D & R Groundworks Limited | Construction | 2008 |
| D and D Cost Savvy Estimation Services Limited | Professional & scientific | 2025 |
| D K Bradford Accountants Ltd | Professional & scientific | 2021 |
| D3 Partnership Limited | Administrative & support | 2023 |
| DAB Consultancy Ltd | Professional & scientific | 2018 |
| DAF Property Investments Ltd | Construction | 2025 |
| Dalmount Engineering Limited | Construction | 2008 |
| Dalroad Distribution Limited | Extraterritorial | 2006 |
| Dampforce Limited | Professional & scientific | 2025 |
| Danefern Limited | Real estate | 1987 |
| Darren LEE Consulting Ltd | Professional & scientific | 2018 |
| Data Rocketship Ventures Ltd | Information & communication | 2019 |
| Dauda Ltd | Real estate | 2024 |
| David Evans Global Associates Limited | Other services | 2022 |
| David Fisher Ltd | Real estate | 2018 |
| David Golden Ltd. | Professional & scientific | 2014 |
| David Harvie Limited | Information & communication | 2005 |
| David Jacobs Estates (Management) Co Ltd | Households | 2026 |
| David Jacobs Properties Limited | Households | 2020 |
| David John Fisher Ltd | Arts & recreation | 2014 |
| David Michael Hussey Limited | Agriculture & fishing | 2007 |
| David Olsson Consulting Limited | Professional & scientific | 2016 |
| Dawn Stores LLP | | 2007 |
| Day Management Consultants Ltd | Professional & scientific | 2018 |
| DB IC Layout Design Ltd | Other services | 2024 |
| DB Strategic Accounts Limited | Professional & scientific | 2023 |
| DBS Skip & Grab Hire Limited | Water & waste | 2016 |
| DC Carpentry & Developments Limited | Construction | 2010 |
| Ddww Consulting Ltd | Professional & scientific | 2014 |
| Dealergen Ltd | Information & communication | 2024 |