| CRE8TIVE Future Ltd | Real estate | 2023 |
| Create Yourself Calm CIC | Health & social care | 2024 |
| Creative Home Improvements Ltd | Construction | 2014 |
| Creative Venture Capital Ltd | Information & communication | 2024 |
| Crestada Limited | Professional & scientific | 2018 |
| Crestmount Design & Energy Ltd | Construction | 2018 |
| Crimson & Elephant Limited | Administrative & support | 2015 |
| Cristi’S Bar Limited | Hospitality | 2023 |
| Croft Farm Snape Camping Ltd | Hospitality | 2025 |
| Croft Farm Snape Cottages Ltd | Hospitality | 2025 |
| Croft Farm Snape Holdings Ltd | Financial services | 2025 |
| Crossed Tipstaves Consulting Ltd | Professional & scientific | 2020 |
| Crossfix Limited | Information & communication | 2017 |
| Crosshairs Grip Rentals Limited | Administrative & support | 2008 |
| Crosshairs Grip Services Limited | Administrative & support | 2008 |
| Crowsheath Farm Country Park Limited | Hospitality | 2019 |
| Croydon Home Help Limited | Health & social care | 2001 |
| Crucible Digital Ltd | Professional & scientific | 2015 |
| Crust Theory Pizza Limited | Hospitality | 2025 |
| CS (Essex) Limited | Real estate | 1999 |
| CS Broking Ltd | Other services | 2009 |
| CS HR Consultancy Ltd | Administrative & support | 2025 |
| CS Hutton Engineering Solutions Limited | Professional & scientific | 2022 |
| CS Refurbishments Ltd | Construction | 2016 |
| Csidedesign Limited | Professional & scientific | 2011 |
| CTO365 Limited | Information & communication | 2022 |
| Cult Couture Clothing Limited | Arts & recreation | 2024 |
| Culture First Consulting Limited | Professional & scientific | 2023 |
| Cunis Limited | Administrative & support | 1994 |
| Curtis Productions Ltd | Professional & scientific | 2016 |
| CV Law Legal Recruitment Agency Ltd | Administrative & support | 2012 |
| CVS Essex Limited | Transport & logistics | 2011 |
| CVT Flooring Ltd | Construction | 2018 |
| Cwgb Ltd | Administrative & support | 2011 |
| CXE Capital LLP | | 2015 |
| Cygnus Healthcare Services Ltd | Health & social care | 2021 |
| CZB Limited | Transport & logistics | 2020 |
| D & G Fire Ltd | Manufacturing | 2008 |
| D & G Property Maintenance Services Limited | Real estate | 2007 |
| D & S Window Solutions Ltd | Construction | 2016 |
| D a M Building Solutions Ltd | Construction | 2021 |
| D Ascott Limited | Professional & scientific | 2013 |
| D Drury Consultancy Limited | Professional & scientific | 2016 |
| D J Palfrey Services Ltd | Financial services | 2017 |
| D S Wager Interiors Ltd | Administrative & support | 2017 |
| D Taylor Property Solutions Ltd | Real estate | 2019 |
| D&L's Investments Limited | Other services | 2024 |
| D&L's Property Development Limited | Real estate | 2024 |
| D' Classic Group Limited | Hospitality | 2019 |
| D'Mello Ice Holdings Ltd | Professional & scientific | 2015 |
| D. E Walker & Associates Limited | Construction | 2010 |
| D. Smith Express Limited | Transport & logistics | 2006 |
| D. Whall Carpentry Limited | Construction | 2010 |
| D.C.K. Concessions Limited | Wholesale & retail | 1992 |
| D.D. Trustees Limited | Extraterritorial | 2007 |
| D.F. Kearney Limited | Administrative & support | 2002 |
| D.J.B. Services Ltd | Construction | 2001 |
| D.J.Goulding Services Limited | Professional & scientific | 2010 |
| D.P. Installations and Maintenance Limited | Manufacturing | 2006 |
| D.W.Rodwell Limited | Construction | 1971 |
| D.Whall Joinery Ltd | Construction | 2026 |
| DAB Hand Art Limited | Construction | 2010 |
| DAB Management Limited | Professional & scientific | 2007 |
| Dagnabell Limited | Wholesale & retail | 2001 |
| Dakota Equestrian Ltd | Wholesale & retail | 2021 |
| Daleside Limited | Other services | 2002 |
| Damson Contract Solutions Limited | Professional & scientific | 2017 |
| DAN Vaughan Motorsport Limited | Professional & scientific | 2018 |
| Dan's Luxury Chauffeurs Ltd | Transport & logistics | 2026 |
| Dance Trix Ltd | Education | 2018 |
| Dandelion Weatherstone C.I.C. | Professional & scientific | 2020 |
| Daniel Ahmed Limited | Real estate | 2025 |
| Daniel Arthur Wassell Ltd | Financial services | 2022 |
| Daniel Darkens Consulting Limited | Professional & scientific | 2022 |
| Daniel James & Partners LLP | | 2006 |
| Daniel James Management Limited | Professional & scientific | 2010 |
| Daniel James Network Limited | Professional & scientific | 2022 |
| Daniel P. Holbrook Ltd | Construction | 2013 |
| Danitech Limited | Information & communication | 1999 |
| DAP & Associates Ltd | Professional & scientific | 2015 |
| Dark Circle Ltd | Arts & recreation | 2010 |
| Dark Moon Holdings Ltd | Financial services | 2024 |
| Dark Soul Tattoo Limited | Other services | 2019 |
| Dark Watch UK Ltd | Administrative & support | 2014 |
| Darling Events Limited | Administrative & support | 2025 |
| Darwin Enterprise Limited | Administrative & support | 2001 |
| Darwin Professional Staffing Group Ltd | Administrative & support | 2013 |
| Darwin Recruitment (UK) Limited | Administrative & support | 2014 |
| Darwin Recruitment Holdings Limited | Administrative & support | 2018 |
| Darwin Recruitment Limited | Administrative & support | 2004 |
| DAS Mixuk Ltd | Transport & logistics | 2023 |
| Datum Property Ltd | Real estate | 2024 |
| Davclo Limited | Manufacturing | 2018 |
| Dave Ball Limited | Professional & scientific | 2013 |
| David Baxter Holdings Limited | Other services | 1999 |
| David Field Decorating Limited | Construction | 2013 |
| David Hodson Engineering Ltd | Professional & scientific | 2018 |
| David Johnson Limited | Arts & recreation | 2020 |
| David Lawrence Furniture Limited | Manufacturing | 2023 |
| David Lloyd Holiday Breaks Limited | Hospitality | 2009 |