| Cornish Spirit Company Limited | Manufacturing | 2012 |
| Cornucopia Holdings Limited | Professional & scientific | 2017 |
| Cosy Corners by G&G Ltd | Wholesale & retail | 2025 |
| Cottage Garden Cats Ltd | Other services | 2022 |
| Country Roads Catering Ltd | Hospitality | 2026 |
| Courtney & Associates Ltd | Professional & scientific | 2018 |
| Coussmaker Limited | Real estate | 2023 |
| CPS Private Staffing Ltd | Administrative & support | 2024 |
| Craftwise Ltd | Professional & scientific | 2023 |
| Crafty Holdings Limited | Financial services | 2021 |
| Crawte Avenue Tenants Management Limited | Households | 2024 |
| Crazy Otter Publishing Ltd | Information & communication | 2025 |
| Creation Management Limited | Administrative & support | 2007 |
| Creation Songs Limited | Information & communication | 1980 |
| Creative Freedom Carpentry Ltd | Construction | 2020 |
| Creative Office Environments Limited | Wholesale & retail | 1992 |
| Creative Source Limited | Professional & scientific | 1989 |
| Crestwood (Southern) Limited | Wholesale & retail | 2001 |
| Crill Carpentry & Construction Ltd | Construction | 2025 |
| Critical Resources (UK) Limited | Information & communication | 2021 |
| Crocks (2025) Ltd | Hospitality | 2025 |
| Crofts and SON Ltd | Construction | 2023 |
| Crosstrees Accountancy and Tax Services Limited | Professional & scientific | 2018 |
| Crowfoot Carpentry Ltd | Construction | 2024 |
| Crowfoot Construction Ltd | Construction | 2022 |
| Crown Road (Enfield) Management Company Limited | Real estate | 2007 |
| Cruinn Diagnostics Limited | Health & social care | 2025 |
| Crunch Catering Ltd | Hospitality | 2024 |
| Crystal Composite Services LLP | | 2010 |
| CSK Marine Welding & Fabrication Limited | Manufacturing | 2015 |
| CSS (Lymington) Ltd | Administrative & support | 2002 |
| CSS Cleaning Contractors Limited | Administrative & support | 2016 |
| CSS Enterprise Limited | Administrative & support | 2019 |
| Cube FBS Limited | Professional & scientific | 2013 |
| Curly Flex Direct Limited | Wholesale & retail | 2009 |
| Curodomus Limited | Real estate | 2016 |
| CY Systems Limited | Manufacturing | 2021 |
| Cylinder Mining Services Ltd | Wholesale & retail | 2025 |
| Czenal Ltd | Manufacturing | 2025 |
| D Cook Properties Ltd | Real estate | 2023 |
| D G Enterprises (Christchurch) Ltd | Professional & scientific | 2018 |
| D Phillips Technical Services Ltd | Professional & scientific | 2018 |
| DA Curtis Property Maintenance Ltd | Professional & scientific | 2018 |
| Daberco Ltd | Education | 2023 |
| Dadd Consultants Limited | Professional & scientific | 2016 |
| DAK Building Design Ltd | Professional & scientific | 2023 |
| DAK Drafting Services Ltd | Professional & scientific | 2020 |
| DAL Controls Ltd | Manufacturing | 2022 |
| DAN Evans Ltd | Construction | 2012 |
| Danewood Holdings Limited | Professional & scientific | 2020 |
| Daniel James London Official Ltd | Manufacturing | 2024 |
| Dare 2 Succeed Ltd | Administrative & support | 2017 |
| Dark Violet Ltd | Other services | 2025 |
| Dash Consult Limited | Professional & scientific | 2025 |
| Dash Management Limited | Real estate | 2022 |
| Dashwood Properties Limited | Real estate | 1964 |
| Dasorp Investment Limited | Financial services | 2025 |
| Data Resources Limited | Professional & scientific | 1995 |
| Daveydown Limited | Wholesale & retail | 2005 |
| David Mackersey Creative Limited | Professional & scientific | 2020 |
| David Samuel Coaching Ltd. | Professional & scientific | 2018 |
| Davis & Co Accountants Ltd | Extraterritorial | 2007 |
| Dbvh at Fibonacci Limited | Construction | 2018 |
| DCO Limited | Information & communication | 2016 |
| Ddfa Limited | Wholesale & retail | 2005 |
| Dealing Technology Limited | Information & communication | 2011 |
| Death Disco 2003 Limited | Hospitality | 2003 |
| Debbie a Chadwick Limited | Health & social care | 2020 |
| Decorfolia Limited | Administrative & support | 1976 |
| Decorum Vending Limited | Wholesale & retail | 2015 |
| Deep Blue FPV Ltd | Information & communication | 2025 |
| Deep Blue Navigation Ltd | Construction | 2026 |
| Deep Red PUB Company Ltd | Hospitality | 2023 |
| Deeracres Limited | Financial services | 1997 |
| Defenda Ltd | Manufacturing | 2020 |
| Delta Humans Limited | Administrative & support | 2009 |
| Dennis Muirhead Company Limited | Arts & recreation | 1982 |
| Dennis Muirhead Music Company Limited | Professional & scientific | 1986 |
| Department One Limited | Information & communication | 2026 |
| Desenfan Limited | Real estate | 2009 |
| Design for Variation Ltd | Professional & scientific | 2023 |
| Destination Profile Limited | Professional & scientific | 2025 |
| Deverell Allen Limited | Professional & scientific | 2016 |
| DHC (Bradford) Limited | Professional & scientific | 1982 |
| Dials Antique Clocks Ltd | Other services | 2025 |
| Dibben Electrical Contractors Limited | Construction | 2011 |
| Digital Drive IT Solutions Limited | Information & communication | 2024 |
| Discontent Ltd | Information & communication | 2018 |
| Discovery Games Limited | Professional & scientific | 2010 |
| Disney Physiotherapy Ltd | Other services | 2025 |
| Diversified Equity Ltd | Real estate | 2018 |
| DJ Education Consultants Ltd | Education | 2008 |
| DL Histed Composites Limited | Manufacturing | 2025 |
| Dlec Electrical Contractors Ltd | Construction | 2013 |
| Domaine DE Combebelle Limited | Professional & scientific | 2005 |
| Dominic James Powers Limited | Extraterritorial | 2025 |
| Domo Sports Grass Contracting Limited | Professional & scientific | 2020 |
| Donaldsona Consulting Ltd | Public administration | 2024 |
| Donhead Design Limited | Real estate | 1999 |
| Doodle & Patch Property Limited | Real estate | 2016 |