| Custom Ecobuild Ltd | Construction | 2022 |
| Custom Scopes Limited | Professional & scientific | 2024 |
| Customer Experience Insights Ltd | Information & communication | 2021 |
| CWG Choices Limited | Manufacturing | 2006 |
| CX Logistics Ltd | Transport & logistics | 2018 |
| Cyber Chain Limited | Information & communication | 2023 |
| Cyclomarket Limited | Wholesale & retail | 1985 |
| Cyffs Ltd | Transport & logistics | 2016 |
| CZC Ltd | Hospitality | 2025 |
| Cérélia UK Ltd | Manufacturing | 2010 |
| D & E Walton Family Investment Company Limited | Other services | 2025 |
| D and D Automotive Limited | Wholesale & retail | 2000 |
| D C Jointing Limited | Construction | 2003 |
| D C Motors Corby Limited | Wholesale & retail | 2022 |
| D F Stewart Services Limited | Water & waste | 2002 |
| D H Sweeney Property Services Limited | Administrative & support | 2007 |
| D J M Contracts Ltd | Construction | 2009 |
| D J Rattigan Builders Limited | Construction | 1997 |
| D K Concrete Limited | Manufacturing | 2006 |
| D Luong Limited | Information & communication | 2015 |
| D M Surveying Limited | Professional & scientific | 2007 |
| D Marin Transport Ltd | Transport & logistics | 2018 |
| D Maxim Logistics Limited | Extraterritorial | 2001 |
| D Moto Ltd | Transport & logistics | 2017 |
| D N Bepswa Limited | Energy | 2025 |
| D Simonds Services Ltd | Wholesale & retail | 2023 |
| D Smith Training Specialists Limited | Administrative & support | 2015 |
| D Stock Consultancy Ltd | Professional & scientific | 2024 |
| D Welsh Engineering Limited | Professional & scientific | 2011 |
| D&A Moto Ltd | Wholesale & retail | 2018 |
| D&C Car Repairs Ltd | Wholesale & retail | 2017 |
| D&G Driving Ltd | Transport & logistics | 2017 |
| D&R Transport Limited | Wholesale & retail | 2025 |
| D-Mac Groundworks Ltd | Construction | 2026 |
| D-Mac Landscaping Ltd | Administrative & support | 2026 |
| D.A.M Wood Coffee Limited | Hospitality | 2026 |
| D.H Fabrication Services Limited | Administrative & support | 2008 |
| D.I.C.E - Electrical Services Ltd | Construction | 2020 |
| Dacea Ltd | Information & communication | 2024 |
| Dacianstransport Ltd | Transport & logistics | 2025 |
| Daily Habits Ltd | Information & communication | 2016 |
| Daily Takeaway Ltd | Hospitality | 2025 |
| Daisy Lane Role Play Ltd | Hospitality | 2025 |
| Daka Building Services Limited | Construction | 2016 |
| Dakota Vehicle Maintenance Limited | Wholesale & retail | 2026 |
| Daksa Transport Ltd | Transport & logistics | 2025 |
| Dale Mckeown - IT Services Limited | Extraterritorial | 2025 |
| Dalom Limited | Health & social care | 2013 |
| Dalyioana&Alina Ltd | Transport & logistics | 2019 |
| Damsun Ltd | Wholesale & retail | 2025 |
| DAN & Sons Haulage Ltd | Transport & logistics | 2018 |
| DAN T Automotive Limited | Wholesale & retail | 2016 |
| DAN Warin Osteopaths Limited | Health & social care | 2010 |
| Danchyk Tech Ltd | Information & communication | 2026 |
| Dandu ADC Ltd | Wholesale & retail | 2026 |
| Danemy Ltd | Transport & logistics | 2020 |
| Daniel & Father Properties Ltd | Real estate | 2026 |
| Daniel Ciucanu Ltd | Wholesale & retail | 2018 |
| Daniel Fast Repair Ltd | Wholesale & retail | 2023 |
| Daniel Zaharia Ltd | Wholesale & retail | 2025 |
| Daniel.H Carpenter Ltd | Manufacturing | 2020 |
| Danix Networks Ltd | Construction | 2026 |
| Danjarvis Limited | Transport & logistics | 2025 |
| Danny & M Limited | Construction | 2015 |
| Dannydarko Consultancy Ltd | Health & social care | 2018 |
| Dannyville Property Investments Ltd | Real estate | 2022 |
| DANTRANS83 Ltd | Wholesale & retail | 2018 |
| Danubias Procurement Solutions Ltd | Wholesale & retail | 2025 |
| Dapira Limited | Health & social care | 2013 |
| DAR Car 77 Ltd | Wholesale & retail | 2024 |
| Dardan Transport Limited | Transport & logistics | 2024 |
| Darla Venus Resource Limited | Administrative & support | 2023 |
| Darlingtons Entertainments Limited | Wholesale & retail | 2004 |
| Darthome Limited | Wholesale & retail | 2017 |
| Data Launch Limited | Administrative & support | 2024 |
| Dattetech UK Ltd | Construction | 2023 |
| DAV Technical Ltd | Wholesale & retail | 2022 |
| Davcar Solutions Ltd | Construction | 2016 |
| Dave & Co Solutions Limited | Administrative & support | 2024 |
| Dave Nicholson Engineering Limited | Professional & scientific | 2024 |
| Davex Limited | Professional & scientific | 2016 |
| David & Dani Auto & Delivery Ltd | Construction | 2026 |
| David G Construct Ltd | Construction | 2023 |
| David Hadingham Consultancy Limited | Hospitality | 2011 |
| David Maxim Haulage Limited | Extraterritorial | 1999 |
| Davidhub Ltd | Transport & logistics | 2019 |
| Davidson Equestrian & Eventing Ltd | Other services | 2022 |
| Davidson Property & Developments Ltd | Other services | 2022 |
| Davidson Training Solutions Ltd | Hospitality | 2020 |
| Davies Family Investments Limited | Wholesale & retail | 2018 |
| Davies Property Solutions Group Limited | Professional & scientific | 2021 |
| Davos Tiling Ltd | Construction | 2018 |
| Davota Ltd | Hospitality | 2023 |
| DAW POL Ltd | Construction | 2017 |
| Dawprep Limited | Wholesale & retail | 2026 |
| Dawu Management Consultants Ltd | Professional & scientific | 2024 |
| DBK Visuals Ltd | Professional & scientific | 2025 |
| DBT Telecom Limited | Wholesale & retail | 2019 |
| DBZ Tutu Ltd | Administrative & support | 2019 |
| DCL Chambers Healthcare Limited | Administrative & support | 2014 |