| D.F. Noble Limited | Financial services | 2009 |
| D.I Spedition Ltd | Construction | 2015 |
| D.I.P.A.M Ltd | Information & communication | 2015 |
| D.J.N. Brickwork Limited | Construction | 2017 |
| D.R.N. Engineering Limited | Manufacturing | 1982 |
| DA Design and Build Ltd | Construction | 2025 |
| DA Progress Limited | Health & social care | 2024 |
| Da&Sons Crew Ltd | Construction | 2023 |
| DAA Express Ltd | Transport & logistics | 2022 |
| Daaru-L-Ilm Islamic Studies | Education | 2023 |
| DAB Project & Commercial Ltd | Professional & scientific | 2026 |
| Dabs Consultancy Ltd | Other services | 2024 |
| DAC Drylining Ltd | Construction | 2017 |
| DAC Trading Ltd | Wholesale & retail | 2026 |
| Dachitrans Limited | Transport & logistics | 2019 |
| DAD IT Service Ltd | Information & communication | 2026 |
| DAD Limited | Manufacturing | 2000 |
| Daffodil Management Services Ltd | Administrative & support | 2023 |
| Daffodils Solicitors Limited | Professional & scientific | 2019 |
| Dagnall Brickwork Limited | Construction | 2010 |
| Dahabo Transport Limited | Transport & logistics | 2019 |
| Daherco Ltd | Wholesale & retail | 2013 |
| Daherrepairs Limited | Manufacturing | 2025 |
| Daian Ioan Ltd | Transport & logistics | 2018 |
| Daijen Limited | Health & social care | 2020 |
| Daily Essentials Luton Limited | Wholesale & retail | 2025 |
| Daily Hub 24 Limited | Wholesale & retail | 2026 |
| Dailytrek Ltd | Wholesale & retail | 2025 |
| Daisy Doo-Licious Ltd | Wholesale & retail | 2026 |
| Daisy Home Care Ltd | Health & social care | 2021 |
| Dakin Contractors Ltd | Construction | 2021 |
| Daklas Ltd | Hospitality | 2023 |
| Dalan UK Ltd | Real estate | 2022 |
| Dale Knight Limited | Wholesale & retail | 2025 |
| Dale Motor Group Limited | Wholesale & retail | 2026 |
| Dalford Traders Limited | Wholesale & retail | 2025 |
| Dalintober Trading Limited | Wholesale & retail | 2021 |
| Dallas SF Properties Limited | Real estate | 2017 |
| Dallimore Decorating Ltd | Construction | 2023 |
| Dallow Development Trust Limited | Health & social care | 2000 |
| Dallow Foods Ltd | Wholesale & retail | 2025 |
| Dallow Minimarket Ltd | Wholesale & retail | 2024 |
| Dallow Road Retail Limited | Wholesale & retail | 2017 |
| Dalroad Norslo Limited | Wholesale & retail | 1993 |
| Dalston Lane Terrace Management Company Limited | Real estate | 2016 |
| DAM Carpentry & Installation Ltd | Construction | 2026 |
| Damac Holdings Ltd | Real estate | 2025 |
| Damasa Limited | Real estate | 2015 |
| Damaya Investments Ltd | Financial services | 2025 |
| Damaya Pharmaceuticals Ltd | Other services | 2024 |
| Damexpress Ltd | Transport & logistics | 2017 |
| Damian Polit Logistics Ltd | Transport & logistics | 2018 |
| Damion Construction Solutions Ltd | Construction | 2017 |
| Damion Limited | Professional & scientific | 1974 |
| Dammie Limited | Wholesale & retail | 2018 |
| Damo Painting & Decorating Ltd | Construction | 2022 |
| Damsel Elite Ltd | Wholesale & retail | 2026 |
| DAN Crick Electrical Limited | Construction | 2018 |
| DAN Davey Aviation Services Ltd | Manufacturing | 2019 |
| DAN Nickless Associates Limited | Other services | 2012 |
| Dan&M Limited | Transport & logistics | 2017 |
| Dana Hudson Productions Ltd | Other services | 2025 |
| Danber Ltd | Health & social care | 2010 |
| Danceminds Collective CIC | Education | 2020 |
| Dane Property Services Limited | Construction | 2019 |
| Daneen Logistics Ltd | Transport & logistics | 2026 |
| Danfar Services Ltd | Wholesale & retail | 2025 |
| Dani Motors Ltd | Wholesale & retail | 2012 |
| Dani Motors South Ltd | Wholesale & retail | 2015 |
| Daniel & Co Brickwork Ltd | Construction | 2013 |
| Daniel Building and Constructions Ltd | Construction | 2025 |
| Daniel E Blake Ltd | Construction | 2018 |
| Daniel HIJ Ltd | Construction | 2015 |
| Daniel Jouanneau Limited | Professional & scientific | 1998 |
| Daniel Painter Ltd | Construction | 2023 |
| Daniel Roman Limited | Transport & logistics | 2014 |
| Daniel SAN Construct Ltd | Information & communication | 2025 |
| Daniel's Jewellers Limited | Wholesale & retail | 2009 |
| Daniel's Plastering Ltd | Construction | 2021 |
| Danielle's Childminding Services Ltd | Health & social care | 2025 |
| Danielm& Paula Limited | Transport & logistics | 2015 |
| Daniem Limited | Wholesale & retail | 2013 |
| Daniyal Limited | Health & social care | 2008 |
| Danjee Business Support Services Ltd | Health & social care | 2023 |
| Dank Duppyz Ltd | Wholesale & retail | 2023 |
| Danny G Carpentry Ltd | Construction | 2023 |
| Dans Legal Limited | Professional & scientific | 2024 |
| Danshay Management Limited | Arts & recreation | 2016 |
| Dantalab Ltd | Wholesale & retail | 2022 |
| Danut Plumbing Ltd | Construction | 2022 |
| Danuta Breban Ltd | Health & social care | 2013 |
| Danwell Living Ltd | Health & social care | 2026 |
| Dany Roof Experts Ltd | Construction | 2024 |
| Dany-Andreea's Ltd | Construction | 2017 |
| Dape Limited | Wholesale & retail | 2023 |
| DAR Al-Salam Properties Ltd | Real estate | 2025 |
| Darbar Karahi Centre Limited | Hospitality | 2024 |
| Dardan Homes Ltd | Construction | 2025 |
| Darek Car Servicing Ltd | Wholesale & retail | 2009 |
| Darjeeling Tea Factory Ltd | Wholesale & retail | 2025 |