| Crisp & Humphreys RTM Company Limited | Households | 2008 |
| Crispy Cookie Ltd | Information & communication | 2024 |
| CRM Roofing Limited | Construction | 2023 |
| CRM Rooms to Homes Ltd | Real estate | 2022 |
| Croak Ltd | Information & communication | 2022 |
| Crofts Consulting Ltd | Professional & scientific | 2023 |
| Crombies Recruitment Limited | Administrative & support | 2018 |
| Cross Hands Meats Limited | Hospitality | 2024 |
| Crosspath Services Limited | Professional & scientific | 1993 |
| Crossways Commercial Estates Limited | Construction | 2005 |
| Crowdahead Limited | Wholesale & retail | 2012 |
| Crown Aesthetics Training Limited | Education | 2019 |
| Crown Commercial Centre Limited | Real estate | 2020 |
| Crownline International Limited | Administrative & support | 2023 |
| Crows Consultancy UK Limited | Administrative & support | 2011 |
| Crowsheath Fishery Ltd | Agriculture & fishing | 2015 |
| Crumbs & Spills Ltd | Hospitality | 2022 |
| Crumptons Heating and Plumbing Specialist Services Ltd | Construction | 2021 |
| Crusy Building Ltd | Other services | 2018 |
| Crystal Accountancy & Tax Ltd | Professional & scientific | 2015 |
| Crystal Rock Coffee House Ltd | Wholesale & retail | 2025 |
| Crystal Waters Management Limited | Professional & scientific | 2025 |
| Crème on Sea Limited | Hospitality | 2018 |
| CS Holdings (Essex) Ltd | Other services | 2025 |
| CS New Street Limited | Construction | 2026 |
| CSF Building Contractors Ltd | Construction | 2010 |
| CSS Construction Services Limited | Construction | 2014 |
| CTC Foods Limited | Hospitality | 2024 |
| CTS Maintenance Limited | Construction | 2009 |
| CULTIV8UK CIC | Agriculture & fishing | 2018 |
| Cultlovesyou Limited | Information & communication | 2015 |
| Cunningham-Weir Limited | Real estate | 2022 |
| Cursed Earth Comics Ltd | Wholesale & retail | 2023 |
| Curtain Design Centre Ltd | Manufacturing | 2002 |
| Curveball Film and TV Limited | Information & communication | 2019 |
| Cushion Supplier Ltd | Manufacturing | 2021 |
| Cutisclear Limited | Health & social care | 2025 |
| CW Plumbing & Heating Limited | Construction | 2018 |
| CW Safety Systems Limited | Public administration | 2018 |
| CWT Partnership Ltd. | Construction | 2003 |
| Cyclops STM Limited | Professional & scientific | 2025 |
| Cyrus Health Limited | Health & social care | 2014 |
| D & G Flat Roofing Systems Limited | Construction | 2020 |
| D & O Investments Limited | Real estate | 2019 |
| D & S Herring Limited | Wholesale & retail | 2003 |
| D & S Hung Limited | Real estate | 2020 |
| D a Ward Plastering Limited | Construction | 2014 |
| D and L Pymer Ltd | Real estate | 2018 |
| D E S Homes Limited | Real estate | 2025 |
| D G Shelley Master Thatcher Limited | Construction | 2011 |
| D Gibson Financial Services Ltd | Financial services | 2008 |
| D J Decorating Ltd | Construction | 2026 |
| D L Food & Leisure Limited | Hospitality | 2019 |
| D M Vehicle Services Limited | Wholesale & retail | 2018 |
| D R Car Care Limited | Wholesale & retail | 2017 |
| D S Electrical Essex Limited | Construction | 2022 |
| D S K Communications Ltd | Other services | 2010 |
| D T Property Management Limited | Real estate | 2000 |
| D Thomas Business Initiatives Ltd | Professional & scientific | 2021 |
| D Ward Plastering Ltd | Construction | 2022 |
| D&G Commercial Builders Limited | Construction | 2022 |
| D&G Maintenance Limited | Construction | 2011 |
| D&H Hospitality Limited | Hospitality | 2026 |
| D&J Real Services Limited | Information & communication | 2025 |
| D&T Property Solutions Ltd | Real estate | 2019 |
| D'Mello Consultants Ltd | Professional & scientific | 2017 |
| D-Tek Services Ltd | Information & communication | 2016 |
| D. a. D. Brickwork Limited | Construction | 2007 |
| D. F. Clark Bionomique Limited | Professional & scientific | 2007 |
| D. Kirk Electrical Services Limited | Construction | 2022 |
| D.A.Clarke Interiors Ltd | Construction | 2017 |
| D.M Build and SON Limited | Construction | 2014 |
| D.R. Matthews Insulations Limited | Construction | 1992 |
| D.R.Burt Ltd | Administrative & support | 2014 |
| D.R.M. Construction Limited | Construction | 2011 |
| D.Sport Media Limited | Professional & scientific | 2026 |
| D.Sport Publishing Limited | Information & communication | 2026 |
| D.W. Stunts Limited | Arts & recreation | 2024 |
| D42 Advisory Ltd | Professional & scientific | 2022 |
| DAA Services Limited | Professional & scientific | 2023 |
| Daily Tasty Limited | Hospitality | 2024 |
| Dakini Bliss RAW Organic Chocolate Company Limited | Manufacturing | 2021 |
| Dalco Ltd | Professional & scientific | 2025 |
| Dalogan Ltd | Financial services | 2025 |
| DAM Taxis Ltd | Extraterritorial | 2023 |
| Damocles Limited | Administrative & support | 2020 |
| Danbury Plumbing Ltd | Construction | 2017 |
| Danceland at Dalbys Ltd | Arts & recreation | 2022 |
| Dandome Limited | Wholesale & retail | 2010 |
| Danebond Limited | Real estate | 2012 |
| Danelektro Ltd | Construction | 2015 |
| Danesleigh Holdings Limited | Professional & scientific | 2022 |
| Dangate Limited | Manufacturing | 1997 |
| Daniel Alexander Recruitment Ltd | Administrative & support | 2014 |
| Daniel Clarke Productions Ltd | Wholesale & retail | 2025 |
| Daniel Harveys (UK) Ltd | Construction | 2015 |
| Daniel Paul Castle Associates Limited | Professional & scientific | 2025 |
| Danik Group Limited | Administrative & support | 2017 |
| Danni Vandenbossche Design Limited | Professional & scientific | 2019 |
| Danpash Limited | Professional & scientific | 2013 |