| Crystal Express Ltd | Construction | 2022 |
| CS Real Estate Ltd | Real estate | 2018 |
| Cubria Consulting Ltd | Professional & scientific | 2025 |
| Curiosity Technology Ltd | Professional & scientific | 2021 |
| Curzon Financial Advisers Ltd | Financial services | 2020 |
| D & a Autos (MOT) Ltd | Wholesale & retail | 2017 |
| D & R Redevelopments Ltd | Construction | 2018 |
| D M Dellow Limited | Construction | 2017 |
| D'Decor Ltd | Construction | 2018 |
| Daddy Source Ltd | Real estate | 2021 |
| DAJ Property Investments Limited | Real estate | 2021 |
| Dalefield (Roebuck Lane) Limited | Households | 1993 |
| Daley Steps Ltd | Health & social care | 2022 |
| Dalston Secret Bakery Limited | Hospitality | 2026 |
| Damien Nash Ltd | Construction | 2014 |
| Dani Burke Private Travel Ltd | Administrative & support | 2016 |
| Daniel Anthony Property Services Limited | Real estate | 2019 |
| Dany Lions Limited | Real estate | 2010 |
| DAR Property Limited | Real estate | 2019 |
| Darren's World Ltd | Wholesale & retail | 2019 |
| Dart Contracting Ltd | Construction | 2018 |
| Dask Services Limited | Professional & scientific | 2007 |
| Data Storytelling Limited | Information & communication | 2021 |
| Datrium Ltd | Information & communication | 2014 |
| Daughters of the Holy Spirit International Women's Fellowship UK Ltd | Professional & scientific | 2022 |
| Daval Properties Limited | Other services | 2012 |
| David Skuse Consultancy Limited | Health & social care | 2008 |
| Davili Healthcare Limited | Health & social care | 2013 |
| Dawmar Limited | Wholesale & retail | 2010 |
| Daya IT Consulting Ltd | Information & communication | 2018 |
| Dclf Wealth Management Limited | Professional & scientific | 2020 |
| Dcrk Investments Ltd | Professional & scientific | 2023 |
| DDD Logistics Ltd | Construction | 2019 |
| DE Buhr Film Ltd | Information & communication | 2016 |
| Deadly Games Film Limited | Information & communication | 2025 |
| Dean Properties Limited | Real estate | 2013 |
| DEE Tees Consulting Ltd | Professional & scientific | 2016 |
| Deeves Hall Developments Ltd | Real estate | 2026 |
| Dello Spirito Limited | Administrative & support | 2011 |
| Delux XP Ltd | Professional & scientific | 2025 |
| Dench Fitness Gym Limited | Arts & recreation | 2017 |
| Dennison Systems Ltd | Construction | 2023 |
| Desa Group Holdings Ltd | Real estate | 2026 |
| Detoga Ltd | Construction | 2019 |
| DEVDEVON1 Ltd | Construction | 2022 |
| Development and Learning (London) Limited | Education | 2013 |
| Diamond Dice Homes Ltd | Hospitality | 2025 |
| Diamond Dice Ltd | Construction | 2021 |
| Digital Financial Limited | Professional & scientific | 2020 |
| Dineary Ltd | Information & communication | 2024 |
| Dineouthalal Ltd | Information & communication | 2023 |
| Dingwall Limited | Construction | 2003 |
| DIRECT2DESK Ltd | Professional & scientific | 2022 |
| Discere Ltd | Professional & scientific | 2024 |
| Distinct Education Services Limited | Education | 2004 |
| District 7 Ltd | Construction | 2026 |
| Diviani Aviation Limited | Transport & logistics | 2012 |
| Django's Coffee Ltd | Hospitality | 2024 |
| DKM Industries Limited | Information & communication | 2026 |
| DM Properties Investments Limited | Real estate | 2025 |
| DM Real Estate (North West) Ltd | Real estate | 2026 |
| Dmiii Productions Ltd | Arts & recreation | 2022 |
| DMO Site Logistics Ltd | Construction | 2013 |
| DMT Property Limited | Real estate | 2016 |
| Dockside Block Management Ltd | Real estate | 2025 |
| Dockside Property Services (East London) Limited | Real estate | 2024 |
| Dockside Property Services (Kent) Limited | Real estate | 2005 |
| Dockside Property Services (Strood) Limited | Real estate | 2014 |
| Dogfender Limited | Administrative & support | 2021 |
| Doggle Ltd | Other services | 2023 |
| Dollis Services Limited | Other services | 2025 |
| Doodle Holdings Limited | Arts & recreation | 2015 |
| Double Helix Ltd | Administrative & support | 2012 |
| Double Yews Group Limited | Construction | 1967 |
| DP Managed Ltd | Real estate | 2025 |
| DR Accounts Ltd | Professional & scientific | 2009 |
| DR Craig Reports Ltd | Wholesale & retail | 2024 |
| DR Fetco Limited | Health & social care | 2023 |
| DR. Digital Health Ltd | Information & communication | 2021 |
| DR. Frugal Ltd | Information & communication | 2026 |
| Dragon Willow Acres Ltd | Real estate | 2017 |
| Dream Town Music Limited | Information & communication | 2018 |
| Drive Revive Essex Ltd | Administrative & support | 2023 |
| DS LUX Homes Ltd | Real estate | 2020 |
| DSG Associates Ltd. | Wholesale & retail | 2003 |
| DSH Medics Limited | Health & social care | 2015 |
| DSL Advisory Services Ltd | Administrative & support | 2025 |
| DSS Arbor Ltd | Financial services | 2025 |
| DSS Contracts Ltd | Financial services | 2014 |
| DSS Dreamsafe Solutions Ltd | Construction | 2025 |
| DSS Investments Ltd | Real estate | 2018 |
| DU4RTE Limited | Professional & scientific | 2022 |
| Duncan Recruitment Ltd | Transport & logistics | 2021 |
| DUX Construction Limited | Construction | 2015 |
| Dvees Ltd | Administrative & support | 2013 |
| Dvees- One Ltd | Health & social care | 2014 |
| DW Decs Ltd | Construction | 2013 |
| Dynamic Electrical and Renewable Solutions Ltd | Construction | 2023 |
| Dynasty Installations Limited | Professional & scientific | 2018 |
| E&A Painting and Decorating Ltd | Construction | 2025 |