| Cura Dining & Events Ltd | Hospitality | 2015 |
| Cureway Ltd | Wholesale & retail | 2024 |
| Custom Reef Aquariums Limited | Manufacturing | 2015 |
| Customer Essential Limited | Professional & scientific | 2002 |
| Cygnet Medical Ltd | Health & social care | 2025 |
| D B Designs Southern Limited | Construction | 2000 |
| D James Building Services Ltd | Construction | 2023 |
| D.C.E. Holne Limited | Manufacturing | 1979 |
| D.L. Leisure Limited | Wholesale & retail | 1986 |
| D.R.S. Holdings (Surrey) Limited | Real estate | 2012 |
| D2 Solutions Limited | Information & communication | 2008 |
| Dalcor Pharma UK Ltd | Professional & scientific | 2015 |
| Dale Millar Consulting Limited | Administrative & support | 2019 |
| Dalon Limited | Information & communication | 2022 |
| Dalta Investments Ltd | Extraterritorial | 2018 |
| Danesdale (Pebble Drive) Limited | Administrative & support | 2009 |
| Dangerous Goods Services Ltd | Professional & scientific | 2020 |
| Daniel Kennington Design Limited | Information & communication | 2015 |
| Daniel's Doggies Ltd | Other services | 2025 |
| Danielle & Daisy Care Ltd | Health & social care | 2019 |
| Danseb Ltd | Administrative & support | 2010 |
| Darkroom Consulting Ltd | Professional & scientific | 2018 |
| Darren Moore Windows Ltd | Construction | 2019 |
| Darted Ltd | Professional & scientific | 2025 |
| Data Mesh Limited | Information & communication | 2021 |
| Datapharm Limited | Information & communication | 2018 |
| David Elmer Consulting Ltd | Professional & scientific | 2017 |
| David Lakin Consultancy Ltd | Professional & scientific | 2025 |
| David Michael Productions Limited | Arts & recreation | 2017 |
| Davies and Zajac Limited | Real estate | 2020 |
| Dawtona UK Ltd | Hospitality | 2023 |
| DB Pro Solutions Ltd | Information & communication | 2008 |
| DBO Ltd | Construction | 2024 |
| DC & CGT Limited | Hospitality | 2012 |
| DC Sound Ltd. | Information & communication | 2009 |
| DCH Operations Ltd | Professional & scientific | 2023 |
| DD Build Limited | Construction | 2025 |
| De@Ne Ltd | Manufacturing | 2019 |
| Deatker Consulting Limited | Professional & scientific | 2022 |
| Decanter Wines Limited | Wholesale & retail | 2003 |
| Dedote Ltd | Professional & scientific | 2025 |
| Delicious Dishes Event Catering Limited | Hospitality | 2025 |
| Deliverz Limited | Construction | 2017 |
| Delphium Limited | Professional & scientific | 2016 |
| Delwyn Properties Limited | Real estate | 2021 |
| Demesne Limited | Real estate | 2020 |
| Dendron Consulting Limited | Information & communication | 1998 |
| Denewood FOX Limited | Other services | 2020 |
| Dennys Brands Limited | Manufacturing | 2012 |
| Dennys Uniforms Limited | Wholesale & retail | 1946 |
| Denting the Universe Ltd. | Professional & scientific | 2016 |
| Denzil Print Limited | Manufacturing | 2001 |
| Denzil Road Properties Limited | Real estate | 2019 |
| Derek Wark Limited | Construction | 2021 |
| Design Eleven Limited | Professional & scientific | 2002 |
| Design Window and Door Systems Limited | Construction | 1990 |
| Determin Limited | Information & communication | 2023 |
| DEV Fusion Technologies Ltd | Wholesale & retail | 2024 |
| DEVALA5 Limited | Health & social care | 2024 |
| Devilfly Games Ltd | Professional & scientific | 2020 |
| Dforce Assist Limited | Information & communication | 2022 |
| Dhcr Ltd | Professional & scientific | 2018 |
| Diabetes-Cutmyrisks.Co.Uk Ltd. | Extraterritorial | 2011 |
| Dialiffy AI (Private) Limited | Information & communication | 2026 |
| Diamond Dogs Grooming Ltd | Professional & scientific | 2018 |
| Diesel Smiths Ltd | Wholesale & retail | 2018 |
| Digital Media Platforms Limited | Professional & scientific | 2014 |
| Digital Paper Ltd | Information & communication | 2004 |
| Digital Savings & Media Limited | Other services | 2026 |
| Digital.Fi Ltd | Information & communication | 2022 |
| Digivator Limited | Professional & scientific | 2024 |
| Dimeny’S Ltd | Health & social care | 2026 |
| Discessio Property Limited | Real estate | 2018 |
| Discover Real London Ltd | Administrative & support | 2023 |
| Discovery RE Ltd | Education | 2013 |
| Display Contractors Limited | Wholesale & retail | 1996 |
| Divine Essence Care Ltd | Health & social care | 2024 |
| DK Plumbing and Facilities Ltd | Construction | 2023 |
| DLT Media (UK) Limited | Transport & logistics | 2001 |
| DMA Signs (Holdings) Ltd | Manufacturing | 2014 |
| DMA Signs Limited | Manufacturing | 2001 |
| Dmcg Global Ltd | Administrative & support | 2020 |
| DNA Digital Marketing Limited | Information & communication | 2025 |
| DOC Pathma Ltd | Health & social care | 2018 |
| Dog Scouts Ltd | Other services | 2019 |
| Domestic Plumbing Services Limited | Construction | 2011 |
| Donmai Limited | Professional & scientific | 2023 |
| Doodle Group Limited | Wholesale & retail | 2022 |
| Dorchester Court Freehold Limited | Households | 2016 |
| Dormation Limited | Construction | 2011 |
| Dormy Estate&Equine Ltd Ltd | Households | 2026 |
| Double Aspect Ltd | Information & communication | 2025 |
| Doubletree TV Limited | Information & communication | 2009 |
| Douglas Global Ltd | Wholesale & retail | 2025 |
| DR Alloy Limited | Other services | 2018 |
| DR Humble Clinical Skincare Ltd | Wholesale & retail | 2013 |
| DR Humble Holdings Ltd | Financial services | 2026 |
| DR Potter Anaesthetic Services Ltd | Professional & scientific | 2025 |
| DR S Pathma Ltd | Health & social care | 2019 |
| DR William Scott Limited | Health & social care | 2018 |