| Cygnet Renewables Limited | Energy | 2022 |
| Cytosorbents Medical UK Limited | Manufacturing | 2022 |
| D a Transport Ltd | Hospitality | 2009 |
| D B Real Estate Ltd | Real estate | 2010 |
| D Dare Limited | Other services | 2009 |
| D P S Coach Works Limited | Wholesale & retail | 1993 |
| D&D of Berkshire Limited | Wholesale & retail | 2015 |
| D&F Consulting Ltd | Information & communication | 2020 |
| D'Arcy Lawson Baker Limited | Administrative & support | 2024 |
| D'Arte Projects Ltd | Construction | 2021 |
| D.A.T.Mechanical Services Limited | Administrative & support | 2007 |
| D21 Capital LLP | | 2017 |
| Dakota Air Services LLP | | 2010 |
| Dalton Franks HR Limited | Administrative & support | 2025 |
| Damach Consulting Limited | Professional & scientific | 2014 |
| Damian Hellyer Ltd | Other services | 2016 |
| DAN Drapes Limited | Manufacturing | 2019 |
| Danchar Consulting Ltd | Professional & scientific | 2016 |
| Daneriver Hydropower Services Limited | Energy | 2014 |
| Daniel Vilar Ltd | Professional & scientific | 2021 |
| Daniella Hunter Ltd | Wholesale & retail | 2024 |
| Darlings Facials Ltd | Other services | 2015 |
| Darren Reynolds Limited | Arts & recreation | 2017 |
| Daruchini Brasserie (Binfield) Ltd | Hospitality | 2019 |
| Daryl Catterall Limited | Transport & logistics | 2017 |
| Data Delivery Services Ltd | Information & communication | 2026 |
| Data Transfer Security Ltd. | Information & communication | 2021 |
| Datecraft Limited | Information & communication | 2009 |
| Davidmarie Limited | Wholesale & retail | 2021 |
| Davidson Thomas Limited | Professional & scientific | 2004 |
| Daybreak Foods Limited | Wholesale & retail | 2009 |
| Daybreak Group Holdings Limited | Financial services | 2023 |
| Daybreak Property Limited | Real estate | 2015 |
| DB Landscape Consultancy Ltd | Professional & scientific | 2011 |
| DB27 Limited | Professional & scientific | 2019 |
| DCT Consultancy Ltd | Professional & scientific | 2023 |
| DDN Advisory Services Limited | Professional & scientific | 2023 |
| DE Freitas Costa Company Limited | Other services | 2019 |
| DE Vinci France Ltd | Construction | 2008 |
| Decimel Ltd | Professional & scientific | 2023 |
| Deeboplus Enterprises Limited | Wholesale & retail | 2026 |
| Deezign Limited | Construction | 2024 |
| Deliver MEP Limited | Construction | 2023 |
| Delivered Health Ltd | Wholesale & retail | 2023 |
| Delta Compliance Limited | Professional & scientific | 2000 |
| Delta Programme Management Consultants Limited | Professional & scientific | 2018 |
| Demure Holdings Ltd | Real estate | 2024 |
| Dencora Homes Limited | Real estate | 1982 |
| Dencora Limited | Real estate | 1980 |
| Dencora Properties Limited | Real estate | 1970 |
| Dencora Securities Limited | Real estate | 1973 |
| Denique Vinum Limited | Wholesale & retail | 2019 |
| Denis Unlimited Limited | Professional & scientific | 2024 |
| Dennis Fung Ltd | Information & communication | 2007 |
| DEP IA1 Ltd | Energy | 2017 |
| Desfs Ltd | Health & social care | 2017 |
| Design LAB Innovation Limited | Professional & scientific | 2017 |
| Destination Services International Ltd | Transport & logistics | 2000 |
| Detailking Group Limited | Wholesale & retail | 2015 |
| Detroit Electric UK Limited | Manufacturing | 2014 |
| Deutschemarques (UK) Ltd | Wholesale & retail | 2024 |
| Deutschemarques Limited | Transport & logistics | 2016 |
| Devasoir Ltd | Construction | 2011 |
| Dewhurst Consultancy Services Limited | Transport & logistics | 2011 |
| Dhillon Stevens Limited | Information & communication | 2003 |
| DHL Entertainment Logistics Limited | Transport & logistics | 2025 |
| DHP (UK) LLP | | 2006 |
| DHR Group Ltd | Financial services | 2025 |
| DI Lusso Properties Ltd | Professional & scientific | 2010 |
| Diagnostic Point Limited | Health & social care | 2019 |
| Dickinson Consulting Ltd | Hospitality | 2014 |
| Diewo Quality Services Limited | Professional & scientific | 2016 |
| Different Limited | Wholesale & retail | 2025 |
| Digital Juggler Limited | Professional & scientific | 2011 |
| Dilena Limited | Professional & scientific | 2010 |
| Dinner for Loners Ltd | Information & communication | 2024 |
| Dirksen Healthcare Limited | Health & social care | 2016 |
| Discover Echo UK Ltd | Professional & scientific | 2019 |
| Disparo Ltd | Professional & scientific | 2021 |
| Distro Design Holdings Ltd | Manufacturing | 2023 |
| Distro Design Ltd | Manufacturing | 2017 |
| DJD Rentals Ltd | Administrative & support | 2026 |
| DJG Furniture Limited | Manufacturing | 2013 |
| DJJ Accountancy & Advisory Ltd | Professional & scientific | 2021 |
| DLS Contract Cleaning Ltd | Administrative & support | 2016 |
| DMM Chauffeur Limited | Transport & logistics | 2019 |
| DMS Landscaping Limited | Households | 2025 |
| DMS Utilities Limited | Households | 2022 |
| Doctorproctorscience Ltd | Other services | 2020 |
| Dog Walks MAN Ltd | Other services | 2024 |
| Domacillion Group Ltd | Real estate | 2021 |
| Donaldsondavis Limited | Administrative & support | 2003 |
| Dorian Dacie Limited | Professional & scientific | 2015 |
| Douglas Lindsay Loans Limited | Financial services | 2019 |
| Dove Properties Limited | Real estate | 2013 |
| Downtree PUB 1 Ltd | Hospitality | 2025 |
| Downtree PUB 2 Ltd | Hospitality | 2025 |
| Downtree PUB 3 Ltd | Hospitality | 2025 |
| Downtree PUB 4 Ltd | Hospitality | 2025 |
| Downtree PUB 5 Ltd | Hospitality | 2025 |