| Cysd UK Limited | Wholesale & retail | 2022 |
| D & a Exchange Ltd | Wholesale & retail | 2022 |
| D & N Lettings Ltd | Real estate | 2020 |
| D a Parts Supply Limited | Wholesale & retail | 2024 |
| D AGE Autos Ltd | Wholesale & retail | 2025 |
| D B Media Limited | Information & communication | 2004 |
| D Entertainment Limited | Information & communication | 2025 |
| D Isopescu Ltd | Construction | 2016 |
| D K Powder Coating Limited | Other services | 2017 |
| D K Vision Ltd | Other services | 2010 |
| D Patel Ltd | Wholesale & retail | 2023 |
| D Solutions Limited | Information & communication | 2009 |
| D&B Commercial and Office Cleaning Ltd | Administrative & support | 2025 |
| D&B Property Consultancy Ltd | Real estate | 2011 |
| D&D London Enterprises Limited | Wholesale & retail | 2025 |
| D&F Foods Ltd | Hospitality | 2025 |
| D&M STR Limited | Construction | 2025 |
| D&S Professional Cleaning Ltd | Administrative & support | 2025 |
| D'S Nail & Makeover Limited | Other services | 2026 |
| D. B. Retail Marketing Limited | Wholesale & retail | 2009 |
| D.H.Lawrence Car Hire Ltd | Administrative & support | 2011 |
| D.I. Recruitment Limited | Wholesale & retail | 2012 |
| D.M. Data Solutions Ltd | Information & communication | 2025 |
| D.M.I.C. Facades Ltd | Construction | 2023 |
| D.M.K. Developments Limited | Construction | 1995 |
| D.N.A Star Limited | Wholesale & retail | 2020 |
| D.O. Retail Marketing Limited | Wholesale & retail | 2010 |
| D.S-Hermes Ltd | Administrative & support | 2019 |
| D.S. Silva Ltd | Construction | 2026 |
| D.Z. Electrical Services Ltd | Construction | 2018 |
| D2I Data Management Limited | Information & communication | 2023 |
| D3VP Consulting Limited | Information & communication | 2017 |
| D4S Bathrooms Ltd | Wholesale & retail | 2022 |
| D4S Heating and Plumbing Ltd | Wholesale & retail | 2019 |
| D8 Services Limited | Construction | 2016 |
| Da'Erona Car Hire Ltd | Transport & logistics | 2023 |
| Dacon Ltd | Construction | 2016 |
| Dada Properties Ltd | Real estate | 2024 |
| Dadacare UK Ltd | Wholesale & retail | 2025 |
| Dadd Property Management Ltd | Real estate | 2015 |
| Dads Property Limited | Real estate | 2017 |
| Daga Entertainment Ltd | Information & communication | 2025 |
| Dahab Services Limited | Administrative & support | 2026 |
| Daiga (UK) Investments Ltd | Administrative & support | 2009 |
| Daily Writava Ltd | Wholesale & retail | 2022 |
| Daily Bird Maintenance Ltd | Real estate | 2025 |
| Daily Essentials Wholesale Ltd | Wholesale & retail | 2024 |
| Daily Holdings Limited | Financial services | 2020 |
| Daily Property Limited | Real estate | 2020 |
| Dailybasix Ltd | Wholesale & retail | 2025 |
| Daisy Nails London Ltd | Other services | 2021 |
| Daliyan Ltd | Real estate | 2020 |
| Dallu's Momo Ltd | Hospitality | 2025 |
| Dalz Ltd | Wholesale & retail | 2025 |
| DAM1 Construction Ltd | Administrative & support | 2025 |
| Damey Ltd | Transport & logistics | 2023 |
| Damoc Ltd | Construction | 2019 |
| DAN Architectural Services Limited | Professional & scientific | 2018 |
| DAN Removals Ltd | Transport & logistics | 2024 |
| DAN Stefan Transport Ltd | Transport & logistics | 2026 |
| Danbeck Limited | Wholesale & retail | 1988 |
| Dance Property Investments Limited | Real estate | 1959 |
| Dani Building Services Ltd | Construction | 2013 |
| Daniel Arseni Ltd | Transport & logistics | 2021 |
| Daniel&Co Transport Limited | Transport & logistics | 2018 |
| Danleo Limited | Administrative & support | 2014 |
| Danny & Lorraine Bennett LLP | | 2019 |
| Danso Developers Limited | Construction | 2021 |
| Danta Properties Ltd | Real estate | 2019 |
| Danyal TM Ltd | Construction | 2023 |
| DAP London Ltd | Wholesale & retail | 2024 |
| Dapatel Limited | Hospitality | 2026 |
| Dapper Hub Ltd | Hospitality | 2023 |
| Dapuk Ltd | Wholesale & retail | 2024 |
| DAR Al-Hamd Ltd | Education | 2025 |
| DAR Property Holdings Ltd | Real estate | 2025 |
| DAR Property Maintenance Ltd | Construction | 2019 |
| Dare Photography Limited | Wholesale & retail | 2026 |
| Dark Falcon Productions Limited | Information & communication | 2015 |
| Dark Horse Luxury Cars Ltd | Administrative & support | 2026 |
| Darkduck Finance Ltd | Financial services | 2023 |
| Darley Fordwaith Limited | Construction | 2014 |
| Darlink Ltd | Real estate | 2025 |
| Dart Shipping Limited | Transport & logistics | 2024 |
| Dash Gadgets Limited | Wholesale & retail | 2015 |
| Dash Traders Ltd | Hospitality | 2012 |
| Dashkart Limited | Wholesale & retail | 2019 |
| Dashworlds Limited | Information & communication | 2010 |
| Dasons ES Ltd | Construction | 2016 |
| Dassm Ltd | Professional & scientific | 2021 |
| Dasw Investment Ltd | Real estate | 2018 |
| Data Cost Management Ltd | Administrative & support | 2015 |
| Data Mind Limited | Administrative & support | 2019 |
| Data Scientist LAB Ltd | Information & communication | 2016 |
| Data Wizz Ltd | Information & communication | 2025 |
| Dataevolve Ltd | Information & communication | 2026 |
| Dataflow Analytics Ltd | Information & communication | 2026 |
| Datalore Consultancy Limited | Information & communication | 2015 |
| Datamatics HR and Consultancy PTE Ltd | Other services | 2018 |
| Datapulse AI Limited | Information & communication | 2025 |