| Cozy Cubs Childminding Ltd | Education | 2026 |
| CP Southend Limited | Administrative & support | 2024 |
| CPC Coatings Ltd | Construction | 2022 |
| CR Property Group Limited | Real estate | 2021 |
| Craftywafty Limited | Wholesale & retail | 2020 |
| Crazy Scents & Love Ltd | Wholesale & retail | 2020 |
| Cream Style Ltd | Wholesale & retail | 2025 |
| Create Driveways and Patios Ltd | Administrative & support | 2019 |
| Creativ Flow Limited | Administrative & support | 2025 |
| Crestway Developments Limited | Real estate | 2012 |
| Crimson Impact Stunts Limited | Arts & recreation | 2025 |
| Crispy COD Canvey Island Ltd | Hospitality | 2020 |
| Crofters IT Limited | Professional & scientific | 2013 |
| Crome Healthcare Ltd | Health & social care | 2024 |
| Cromwell Markets Ltd | Professional & scientific | 2019 |
| Crow Field Solutions Ltd | Professional & scientific | 2025 |
| Crumble Cottage Limited | Administrative & support | 2013 |
| Cruse Property Rentals Ltd | Real estate | 2026 |
| Crushes Manor Clinic Limited | Health & social care | 2014 |
| Crystalade Ltd | Wholesale & retail | 2013 |
| CSK Building Works Limited | Construction | 2024 |
| CT Electrcial Contractors Ltd | Construction | 2026 |
| CTB DRY Cleaners Limited | Other services | 2015 |
| CTC Business Operations Limited | Construction | 2025 |
| Culinary Emporium Ltd | Hospitality | 2026 |
| Cullen Mill Property Developments 2025 Limited | Construction | 2025 |
| Cureo Construction Limited | Construction | 2018 |
| Cutting Edge (Sets) Ltd | Other services | 2007 |
| Cutting Edge Live Limited | Other services | 2023 |
| CXH Flooring Ltd | Construction | 2026 |
| CYB Limited | Administrative & support | 1990 |
| CYB Support Limited | Administrative & support | 2019 |
| Cyberdan Limited | Information & communication | 2002 |
| D & D Ductwork Manufacturing Ltd | Manufacturing | 2024 |
| D & M Leftly & Sons Ltd | Water & waste | 2007 |
| D & M Maintenance Limited | Construction | 2003 |
| D Brown Property Ltd | Construction | 2021 |
| D M Utility Services Ltd | Construction | 2018 |
| D Repositioning Ltd | Real estate | 2024 |
| D&C Mastic's Limited | Construction | 2025 |
| D&G Baltic Ltd | Wholesale & retail | 2007 |
| D&G Globe Ltd | Wholesale & retail | 2021 |
| D&G Technology Ltd | Information & communication | 2018 |
| D&H Contractors Ltd | Construction | 2012 |
| D&J Digital Ventures Ltd | Wholesale & retail | 2023 |
| D. P. Leisure Consultancy Ltd | Professional & scientific | 2022 |
| D.C. Demolition & Construction Ltd | Construction | 2013 |
| D.R. Bullock Builders Limited | Construction | 1984 |
| D.R. Ikua Ltd | Health & social care | 2025 |
| D2L Properties Ltd | Real estate | 2023 |
| Dadds LLP | | 2010 |
| Daily Assist UK Ltd | Health & social care | 2026 |
| Danny Green Limited | Construction | 2024 |
| Dape Supplies Limited | Construction | 2019 |
| Darleys Forge Management Company Limited | Real estate | 2024 |
| Darpez Construction Ltd | Construction | 2025 |
| Darryl Claxton Interiors Limited | Administrative & support | 2019 |
| Daskal Properties Limited | Real estate | 2023 |
| Data Bustle Ltd | Information & communication | 2022 |
| Data Navigate Ltd | Wholesale & retail | 2023 |
| Datolami Limited | Health & social care | 2022 |
| Dats Freight Ltd | Transport & logistics | 2016 |
| Dauntless Boatyard Limited | Manufacturing | 1997 |
| Davies’ Drainage Ltd | Water & waste | 2023 |
| DB Motorcycle Logistics Limited | Transport & logistics | 2022 |
| DB Shack Limited | Hospitality | 2022 |
| DC 94 Ltd | Transport & logistics | 2017 |
| DC Motors Essex Ltd | Wholesale & retail | 2025 |
| Dcreed Ltd | Construction | 2025 |
| DCS Overview Limited | Administrative & support | 2024 |
| Dean Macey Ltd | Information & communication | 2014 |
| Decanters Canvey Ltd | Hospitality | 2026 |
| Deed Connect Limited | Information & communication | 2025 |
| DEJO4SURE Ltd | Health & social care | 2023 |
| DEL Tailors Ltd | Wholesale & retail | 2010 |
| Delfin Caffe Ltd | Hospitality | 2018 |
| Deliver Local App Limited | Transport & logistics | 2026 |
| DEM Waste Management Ltd | Water & waste | 2015 |
| Denby Carnarton Limited | Information & communication | 2008 |
| Denise Fowler Limited | Administrative & support | 2019 |
| DES Fire and Security Limited | Manufacturing | 2020 |
| DES Locksmiths Limited | Manufacturing | 2019 |
| Design 4 Print.Com.Uk Limited | Manufacturing | 2001 |
| Deskdecorationsco Ltd | Wholesale & retail | 2025 |
| Devc Ltd | Information & communication | 2017 |
| DG19 Limited | Construction | 2019 |
| DGM Plastering Services Ltd | Construction | 2023 |
| Dhrf Holdings Limited | Financial services | 2024 |
| Diggines Construction Services Limited | Construction | 2024 |
| Dilan Fabrications Ltd | Manufacturing | 1998 |
| DIM Energy Ltd | Construction | 2020 |
| Direct Core Limited | Construction | 2008 |
| Direct Logistics Solutions Ltd | Administrative & support | 2026 |
| District Finalist Limited | Arts & recreation | 2024 |
| Divine Designs UK Limited | Wholesale & retail | 2026 |
| DJF Financial Consultants Ltd | Professional & scientific | 2021 |
| DJL (Travel Consultants) Limited | Administrative & support | 2011 |
| DJM Brickwork Ltd | Construction | 2023 |
| DJR Global Properties Ltd | Real estate | 2026 |
| DKL Consultancy Limited | Information & communication | 2026 |