| Corbierre Consultancy Limited | Professional & scientific | 2010 |
| Coscip Ltd | Wholesale & retail | 2023 |
| Cosmin Maravela Ltd | Health & social care | 2015 |
| Cottage Aesthetics Clinic Ltd | Health & social care | 2019 |
| Country Gardens & Landscapes Limited | Administrative & support | 2017 |
| Cove Coffee Ltd | Hospitality | 2023 |
| Cowell and Cooper Limited | Manufacturing | 2018 |
| CP Packaging Ltd | Administrative & support | 2009 |
| CPA Roofing Ltd | Construction | 2024 |
| CPS Transport Ltd | Transport & logistics | 2017 |
| Craft Rendering & Plastering Limited | Construction | 2018 |
| Craig Martin Events Limited | Hospitality | 2023 |
| Creative FIX Limited | Administrative & support | 2011 |
| CREE8 Projects Ltd | Construction | 2024 |
| Cristal Healthcare and Domiciliary Ltd | Administrative & support | 2023 |
| Crookedwoods Ltd | Wholesale & retail | 2024 |
| CS Biomass Services Ltd | Construction | 2024 |
| CS Courier Transport Limited | Transport & logistics | 2016 |
| CSM Accounting Services Ltd | Professional & scientific | 2010 |
| CSP 888 Ltd | Hospitality | 2024 |
| Cuinspec Ltd | Manufacturing | 2023 |
| Culbin Regulatory Consulting Ltd | Professional & scientific | 2024 |
| Currentpro Solutions Ltd | Wholesale & retail | 2026 |
| Cuthberts Coaching Ltd | Arts & recreation | 2024 |
| CV Storage Limited | Transport & logistics | 2023 |
| CWC Electrics Limited | Construction | 2021 |
| Cwts Civils Ltd | Construction | 2025 |
| CXG Group Limited | Real estate | 2002 |
| CXG Lettings Limited | Real estate | 2007 |
| Cymaz Accounting Ltd | Professional & scientific | 2021 |
| D Fine Haverhill Limited | Other services | 2012 |
| D Sparrow Electrical Ltd | Construction | 2007 |
| D.G. Landscapes & Sons Limited | Administrative & support | 2015 |
| D.N.T Wilson Properties Ltd | Real estate | 2025 |
| D2.DUA&PVT. Limited | Wholesale & retail | 2025 |
| Daines-Lowe Ltd | Wholesale & retail | 2021 |
| Daines-Lowe Projects Ltd | Information & communication | 2023 |
| Daines-Lowe Property Investments Ltd | Real estate | 2025 |
| Damycra Limited | Information & communication | 2011 |
| DAN & Roberta Trans Ltd | Transport & logistics | 2019 |
| Dane Cottage Management Company Limited | Households | 2006 |
| Daniel Fish Bar Limited | Hospitality | 2025 |
| Dare Construction Management Limited | Professional & scientific | 2015 |
| Daryan Transport Ltd | Transport & logistics | 2025 |
| Data Path Design Limited | Information & communication | 2007 |
| Datastation Holdings Limited | Extraterritorial | 2012 |
| Datastation Limited | Administrative & support | 2004 |
| David Hudson Roofing Limited | Construction | 2013 |
| David Lowe DJ Ltd | Information & communication | 2025 |
| Davis Garden Services Ltd | Administrative & support | 2024 |
| DBA Solutions Ltd | Construction | 2025 |
| DCB Plumbing & Heating Limited | Construction | 2021 |
| DCM Motorsport Ltd | Wholesale & retail | 2025 |
| DCN Sameday Ltd | Transport & logistics | 2023 |
| DDB Property Ltd | Real estate | 2022 |
| DDH Recruitment Ltd | Administrative & support | 2009 |
| DEB Consulting & Construction Services Ltd | Construction | 2022 |
| Defence and Fitness Rooms Limited | Arts & recreation | 2019 |
| Defence Leaders Limited | Public administration | 2009 |
| Dental Applications Limited | Health & social care | 2003 |
| Desh Enterprise Ltd | Hospitality | 2024 |
| Desiland Ltd | Hospitality | 2014 |
| DEV Management Limited | Real estate | 2007 |
| Devrella Ltd | Professional & scientific | 2020 |
| Devyani Gupta Limited | Administrative & support | 2025 |
| Dexter Partnerships Limited | Professional & scientific | 2020 |
| Dialpilot Ltd | Wholesale & retail | 2025 |
| Diamond Controls (EA) Limited | Manufacturing | 2018 |
| Digby Stride Ltd | Professional & scientific | 2017 |
| Digi Europe Ltd. | Manufacturing | 1989 |
| Digi European Centre Limited | Manufacturing | 1988 |
| Digital Office Copiers Ltd | Wholesale & retail | 2022 |
| Digital Technology Ventures Ltd | Information & communication | 2013 |
| Dilhus Property Limited | Real estate | 2023 |
| Dilloways Limited | Professional & scientific | 2007 |
| DIR Property Limited | Real estate | 2025 |
| Dizzy's Day Nursery Limited | Education | 2013 |
| DJR Care Ltd | Wholesale & retail | 2023 |
| DM Clerkin Ltd | Construction | 2022 |
| DMA Transport Ltd | Transport & logistics | 2017 |
| DMV Trans Ltd | Transport & logistics | 2025 |
| Dominion Financial Review Limited | Education | 2025 |
| DON Construction Chemicals Limited | Manufacturing | 1997 |
| DON Construction Holdings Limited | Financial services | 2011 |
| DON Construction Limited | Extraterritorial | 2017 |
| DON Construction Products Limited | Manufacturing | 1980 |
| Dora Care Ltd | Health & social care | 2018 |
| Doric Computer Systems International Limited | Information & communication | 1991 |
| Doryuki Ltd | Wholesale & retail | 2023 |
| DOT Training Limited | Education | 2018 |
| Downton Homes Haverhill Limited | Real estate | 2009 |
| DPM Hire Solutions Ltd | Administrative & support | 2019 |
| DPR Accountancy Limited | Professional & scientific | 2001 |
| DPR Solutions Ltd | Construction | 2025 |
| Dragos Transport Ltd | Transport & logistics | 2011 |
| DRB Access Limited | Construction | 2025 |
| Drcj Consulting Ltd | Professional & scientific | 2018 |
| Drive Green Vehicle Services Ltd | Wholesale & retail | 2020 |
| DRM Contracts Ltd | Construction | 2020 |
| DRT Landscapes & Groundworks Ltd | Administrative & support | 2020 |