| Cranworth Farm Services Ltd | Manufacturing | 2023 |
| CRE8IVE Hair Studio Ltd | Other services | 2013 |
| Creative Displays (U.K.) Ltd. | Wholesale & retail | 1992 |
| Creative Penguin Graphics Limited | Information & communication | 2019 |
| Cromwell Estates Limited | Agriculture & fishing | 1999 |
| Crop Angel Limited | Agriculture & fishing | 2015 |
| Crown Construction Anglia Limited | Construction | 2021 |
| Crown Fire Protection Ltd. | Manufacturing | 1995 |
| Crown House Ltd | Health & social care | 2024 |
| Crown Joolz Limited | Wholesale & retail | 2004 |
| Crown Stone Heritage Supplies Ltd | Wholesale & retail | 2025 |
| Croxton Fish Bar Limited | Hospitality | 2019 |
| Croxton Park Limited | Agriculture & fishing | 1955 |
| CRW Developments Limited | Real estate | 2013 |
| CSL Solutions Ltd | Professional & scientific | 2020 |
| Cuckoo Lodgings Ltd | Real estate | 2016 |
| Cultured Builds Ltd | Construction | 2018 |
| Cunning Creative Ltd | Professional & scientific | 2019 |
| Cunningham Motors Limited | Wholesale & retail | 2002 |
| Cushion Manufacturing Supplies Limited | Manufacturing | 2015 |
| Cutting Electrical Contractors Ltd | Construction | 2025 |
| Cyds Drivers Limited | Transport & logistics | 2017 |
| Cygnet Rise Residents Management Company Limited | Households | 2024 |
| D & P Contractors Ltd | Construction | 2022 |
| D & S Pallets Limited | Wholesale & retail | 2013 |
| D & S Stannard Builders Limited | Construction | 2025 |
| D Welling & SON Ltd | Construction | 2019 |
| D&D International Bakery Limited | Manufacturing | 2024 |
| D&L International Limited | Wholesale & retail | 2019 |
| D.J. Raker Limited | Agriculture & fishing | 1948 |
| Dads Army Museum Thetford Ltd | Arts & recreation | 2011 |
| Daisy Homes Ltd | Construction | 2008 |
| Dakam Furniture Ltd | Wholesale & retail | 2025 |
| Dakohome Ltd | Real estate | 2020 |
| DAN Home Care Limited | Health & social care | 2024 |
| DAN Travel Services Limited | Transport & logistics | 2026 |
| Danica Tax Consultancy Ltd | Professional & scientific | 2013 |
| Darren Mead Carpets Limited | Wholesale & retail | 2014 |
| DAS Composites Ltd | Manufacturing | 2019 |
| Datum Manufacturing Ltd | Manufacturing | 2025 |
| Datum Solutions Ltd | Construction | 2021 |
| Dave's Emporium Limited | Wholesale & retail | 2010 |
| David Ovens Ltd | Professional & scientific | 2025 |
| David Stannard Decorating Limited | Construction | 2026 |
| Davies Family Property Management Ltd | Real estate | 2025 |
| Dawe Estates Limited | Agriculture & fishing | 1996 |
| DB Timber Structures Ltd | Construction | 2024 |
| DCG International Ltd | Wholesale & retail | 2021 |
| Dean Stannard Limited | Construction | 2014 |
| DEC0DE Consulting Ltd | Professional & scientific | 2021 |
| Decoilers and Feeders Ltd. | Manufacturing | 2014 |
| Delicje Mimi Ltd | Wholesale & retail | 2022 |
| Denel Property Group Ltd | Real estate | 2026 |
| Dereham Plant and Transport Engineering Limited | Wholesale & retail | 1988 |
| Derwowski Ltd | Information & communication | 2022 |
| Desi Bites Food & Catering Ltd | Wholesale & retail | 2025 |
| DI International Group (Holdings) Limited | Financial services | 2019 |
| Diamond Coat Ltd | Construction | 2023 |
| Diamond Developments Anglia Limited | Construction | 2023 |
| Digital Deterrent Ltd | Administrative & support | 2026 |
| Digital Duck Limited | Information & communication | 2025 |
| Digital Learning Certification Service Limited | Education | 2020 |
| Dilek Fish & Chips Ltd | Hospitality | 2012 |
| Discover Developments Limited | Real estate | 2021 |
| Discover Hair Ltd | Other services | 2005 |
| Disher CAD Services Ltd | Professional & scientific | 2025 |
| DJ Owen Lime and Listed Ltd | Construction | 2025 |
| DJD Plumbing and Heating Eco Ltd | Construction | 2023 |
| DM & KK Enterprises Ltd | Wholesale & retail | 2017 |
| DM Gould Heating and Plumbing Ltd. | Construction | 2023 |
| Dmitrij Ltd | Transport & logistics | 2025 |
| DMR Technicians Ltd | Extraterritorial | 2024 |
| Domaination Limited | Information & communication | 2017 |
| Door to Door Airport Transfers-Thetford Ltd | Transport & logistics | 2026 |
| Doorstep Tyre Fitting Ltd | Wholesale & retail | 2020 |
| Dorvision Ltd | Construction | 2021 |
| Dotstack Ltd | Wholesale & retail | 2025 |
| Double Quick (Heating) Limited | Wholesale & retail | 1999 |
| Doublerretails Ltd | Wholesale & retail | 2025 |
| Down Melody Lane Ltd | Arts & recreation | 2024 |
| Dowsing Plumbing & Heating Ltd | Construction | 2024 |
| Dpvg Limited | Transport & logistics | 2019 |
| DR Demuth UK Ltd | Wholesale & retail | 2026 |
| Dr.Bg Electric Ltd | Construction | 2024 |
| Dragan Homes Ltd | Real estate | 2025 |
| Dragon Imports Limited | Wholesale & retail | 2023 |
| Dreamcanyon Limited | Information & communication | 2025 |
| Dressed to the Canines Ltd | Manufacturing | 2022 |
| Drive-Safe MOT Testing Station Ltd | Wholesale & retail | 2024 |
| Driver Request Ltd | Transport & logistics | 2024 |
| Drone Imagery Ltd | Professional & scientific | 2018 |
| Drummond Electrical Ltd | Construction | 2015 |
| Dtridee Ltd | Agriculture & fishing | 2025 |
| Ductwork Ventilation Systems Limited | Professional & scientific | 2017 |
| DVL & Co Accountants Ltd | Professional & scientific | 2023 |
| Dyer Livestock Limited | Agriculture & fishing | 2004 |
| E J Blackmore Ltd | Agriculture & fishing | 2022 |
| E-Riders Competitions Limited | Arts & recreation | 2018 |
| E.C Newall Holdings Limited | Financial services | 2020 |
| E.W.Porter and SON | Agriculture & fishing | 1958 |