| Curado Ltd | Health & social care | 2011 |
| Cure Quest Limited | Health & social care | 2023 |
| Curness Trading Ltd | Hospitality | 2019 |
| Curtain Management Holdings Limited | Hospitality | 2016 |
| Curzon Tax and Accounting Ltd | Professional & scientific | 2021 |
| Cushy Puff Limited | Manufacturing | 2024 |
| Custom Engraving (Coulsdon) Ltd | Professional & scientific | 2015 |
| Custom Wonderland Ltd | Wholesale & retail | 2017 |
| Cutatwaterloo and Nails Studio Ltd | Other services | 2021 |
| Cutthrough Ltd | Information & communication | 2012 |
| CV Homes Ltd | Real estate | 2020 |
| CVS Business Ltd | Manufacturing | 2017 |
| CW Property Management Ltd | Real estate | 2018 |
| CW Thorning Ltd | Health & social care | 2023 |
| CW Trade Centre Ltd | Wholesale & retail | 2017 |
| CWL International Consultancy Ltd | Other services | 2022 |
| CWM Plumbing & Heating Ltd | Manufacturing | 2015 |
| CWP Facility Management Ltd | Construction | 2023 |
| CYC Investment Limited | Financial services | 2018 |
| Cyclone Global Ltd | Information & communication | 2017 |
| Cyntech Trading Limited | Wholesale & retail | 2000 |
| Cyra Lounge Limited | Hospitality | 2024 |
| D & B Service & MOT Centre Limited | Wholesale & retail | 2009 |
| D & V Property Maintenance Limited | Construction | 2008 |
| D & Y Construction Limited | Construction | 2018 |
| D Accountancy Limited | Professional & scientific | 2023 |
| D and B Coachworks Limited | Wholesale & retail | 2007 |
| D and G Services Limited | Administrative & support | 1999 |
| D D a International Limited | Education | 2003 |
| D D a Property Ltd | Real estate | 2019 |
| D Fields Holdings Ltd | Financial services | 2022 |
| D Fields Investments Ltd | Real estate | 2022 |
| D Fields Property Management Ltd | Real estate | 2023 |
| D K Properties Surrey Ltd | Real estate | 2024 |
| D L Comm Limited | Administrative & support | 2004 |
| D P Car Sales Limited | Wholesale & retail | 2017 |
| D Potter Electrical Ltd | Construction | 2017 |
| D Sharp Design & Build Ltd | Construction | 2025 |
| D&B Property (SWL) Ltd | Real estate | 2025 |
| D&D Daily Sale Ltd | Wholesale & retail | 2020 |
| D&M FIX Ltd | Construction | 2022 |
| D&M Partners Ltd | Real estate | 2024 |
| D&W London Limited | Real estate | 2020 |
| D'Lima Ltd | Health & social care | 2013 |
| D. Powell Surveying Ltd | Construction | 2015 |
| D.Green & Co.(Stoke Newington)Limited | Professional & scientific | 1952 |
| D.N.P Management Ltd | Administrative & support | 2024 |
| D4F Limited | Information & communication | 2025 |
| DA Viability Consulting Ltd | Professional & scientific | 2025 |
| DAB Transport London Limited | Transport & logistics | 2023 |
| Dabis Medico Legal Services Ltd. | Professional & scientific | 2007 |
| Dabsy Ltd | Hospitality | 2024 |
| Dacian Barbers Ltd | Health & social care | 2015 |
| Daedalon Systems Limited | Information & communication | 2026 |
| Dagwoodlinnetts Ltd | Arts & recreation | 1969 |
| DAJ Autos Ltd | Wholesale & retail | 2024 |
| DAK Building Ltd | Construction | 2018 |
| DAL Property Holdings Ltd | Real estate | 2025 |
| Dalali Software Limited | Information & communication | 1983 |
| Dale Fencing and Garden Maintenance Limited | Extraterritorial | 2023 |
| Dale Fencing Limited | Manufacturing | 1974 |
| Dales Capital Ltd | Wholesale & retail | 2024 |
| Daleyz Enterprise Limited | Real estate | 2017 |
| Dallas Court Limited | Real estate | 2001 |
| Dalton LEE Developments Limited | Real estate | 2021 |
| Damien Ltd | Construction | 2011 |
| DAN-3 Ltd | Information & communication | 2025 |
| Daniel Violet Limited | Real estate | 2024 |
| Daniella B Construction Ltd | Construction | 2025 |
| Danielll Ltd | Real estate | 2026 |
| Danny Projects Ltd | Manufacturing | 2014 |
| Danny's Colour Ltd | Construction | 2018 |
| Danojo Limited | Wholesale & retail | 2020 |
| Dansales Ltd | Extraterritorial | 2025 |
| Dansmo Services Limited | Construction | 2026 |
| Dansoaahlondon Limited | Wholesale & retail | 2024 |
| Dany Consulting Services Ltd | Information & communication | 2025 |
| Danyame's Kitchen Limited | Hospitality | 2023 |
| Daprano Consulting Ltd | Information & communication | 2026 |
| Daras Cleaning Services Ltd | Administrative & support | 2019 |
| Dark Accounting Limited | Professional & scientific | 2023 |
| Dark Cyber Sabers Ltd | Wholesale & retail | 2022 |
| Dashkat Limited | Information & communication | 2011 |
| Data & Insight Consultancy Limited | Information & communication | 2021 |
| Dataandnetworksolutions Ltd | Information & communication | 2015 |
| Dataarc Consulting Ltd | Information & communication | 2026 |
| Dataduo Consulting Services Limited | Professional & scientific | 2023 |
| Dataesque IT Solutions Limited | Information & communication | 2018 |
| Datagility Solutions Limited | Financial services | 2017 |
| Datahedron Ltd | Information & communication | 2021 |
| Datawaveai Ltd | Information & communication | 2025 |
| Datazentist Limited | Information & communication | 2017 |
| Dati Clean Move Ltd | Transport & logistics | 2026 |
| Davey Scaffolding Services Limited | Construction | 2008 |
| David Fitness Consultancy Limited | Professional & scientific | 2025 |
| David Hopley Associates Limited | Professional & scientific | 2015 |
| David Irwin Limited | Real estate | 1965 |
| Davista Property Solutions Ltd | Real estate | 2018 |
| Dawkins and Grant Limited | Real estate | 2021 |
| Dawn Fresh Produce Limited | Wholesale & retail | 2003 |