| CTY Limited | Transport & logistics | 2025 |
| Cure DM Ventures CIC | Health & social care | 2017 |
| Curly's Athletes Limited | Arts & recreation | 2016 |
| Custom KIT 4 Ltd | Manufacturing | 2018 |
| Cusworth Flooring Services Limited | Wholesale & retail | 2008 |
| Cuzmok Limited | Transport & logistics | 2024 |
| Cwci Inc Ltd | Administrative & support | 2012 |
| CWL Customs Clearance Brokers Ltd | Transport & logistics | 2020 |
| Cyan Future Limited | Information & communication | 2014 |
| Cymarc Engineering Limited | Manufacturing | 1999 |
| D & K Smith Limited | Wholesale & retail | 2008 |
| D & KH Properties Limited | Households | 2022 |
| D & M Reinforcements Limited | Construction | 2024 |
| D B Newton Limited | Construction | 2015 |
| D C and B Farming Limited | Agriculture & fishing | 2013 |
| D Cooper Consulting Ltd | Professional & scientific | 2024 |
| D I Accountants Ltd | Professional & scientific | 2014 |
| D J Logistics Limited | Transport & logistics | 2013 |
| D J S Housing Limited | Real estate | 2003 |
| D Munday Medical Services Limited | Health & social care | 2019 |
| D R Plumbing & Heating (North) Limited | Construction | 2009 |
| D S Projects Lincolnshire Limited | Construction | 2020 |
| D Simons Limited | Extraterritorial | 2022 |
| D Turner & Co (1953) Limited | Professional & scientific | 2015 |
| D W Forklift Services Limited | Wholesale & retail | 2008 |
| D W Hire and Sales Ltd | Wholesale & retail | 2019 |
| D&G Pest Control Limited | Professional & scientific | 2025 |
| D&J T Transport Ltd | Transport & logistics | 2021 |
| D&K Communications Ltd | Information & communication | 2021 |
| D&S UK Living Ltd | Real estate | 2025 |
| D'Cruz Dermatology Ltd | Health & social care | 2026 |
| D. Grigaitis Ltd | Wholesale & retail | 2017 |
| D.A.C Barbeque Limited | Hospitality | 2021 |
| D.G.B. Property (Investments) Limited | Real estate | 2007 |
| D.M. Roberts Decorator Ltd | Construction | 2003 |
| Daedalus Engineering Services Ltd | Professional & scientific | 2015 |
| DAH Anaesthesia Services Limited | Health & social care | 2022 |
| Dahlia Boutique Ltd | Wholesale & retail | 2021 |
| Daisy Lettings Ltd | Real estate | 2023 |
| Dakuni Limited | Financial services | 1979 |
| Daleari Ltd | Administrative & support | 2024 |
| Damisa Cars Limited | Wholesale & retail | 2025 |
| DAN MIT Ltd | Administrative & support | 2025 |
| Dana's Help for Hiwa Hospital Limited | Health & social care | 2023 |
| Dandi's Diner Limited | Hospitality | 2009 |
| Dangle Access Services Ltd | Construction | 2025 |
| Daniah Consultancy Limited | Health & social care | 2014 |
| Daniel Antcliff Limited | Other services | 2007 |
| Danmar Productions Ltd | Information & communication | 2023 |
| Danny Solts Limited | Health & social care | 2024 |
| Darcy & Bloom Ltd | Wholesale & retail | 2025 |
| Dariaalesia ELT Ltd | Wholesale & retail | 2025 |
| Darion T Delivery Ltd | Transport & logistics | 2024 |
| Darius DDT Ltd | Transport & logistics | 2024 |
| Darius Ionut Ltd | Transport & logistics | 2023 |
| Dariusz Jedryszczyk Transport Ltd | Transport & logistics | 2019 |
| Dariusz Jezierski Ltd | Transport & logistics | 2014 |
| Dark Park Ltd | Arts & recreation | 2010 |
| Dark Tribe Brewery Limited | Manufacturing | 2016 |
| Dary Trans Ltd | Transport & logistics | 2024 |
| Dashcams Limited | Administrative & support | 2018 |
| Dashmed Limited | Health & social care | 2016 |
| Dave Kaye’S Commercial Windows and Doors Ltd | Construction | 2019 |
| David Armando Delivery Ltd | Transport & logistics | 2024 |
| David Barlow Printers Limited | Administrative & support | 2009 |
| David FOX Agricultural Contractors Limited | Agriculture & fishing | 2014 |
| David Gongu Transport Ltd | Transport & logistics | 2025 |
| David Stefy Transport Ltd | Transport & logistics | 2025 |
| David Transport Ltd | Transport & logistics | 2026 |
| David Walker ENT Limited | Health & social care | 2020 |
| Davidovs Holdings Ltd | Real estate | 2025 |
| Davis Development Management Limited | Construction | 2011 |
| Dbonner Piping Ltd | Construction | 2025 |
| DC (Property Holdings) Limited | Administrative & support | 2009 |
| DC Care Limited | Health & social care | 2007 |
| DC Cooling Solutions Ltd | Construction | 2014 |
| DCB Dunn Health & Safety and Environmental Services Ltd | Professional & scientific | 2009 |
| DCI Services Limited | Construction | 2020 |
| Dcsp Ltd | Transport & logistics | 2025 |
| Dead Duck Automotive Ltd | Wholesale & retail | 2025 |
| Dealgrove Properties Limited | Real estate | 1988 |
| Dean Fielding Limited | Construction | 2021 |
| Deaton-Castillo Properties Ltd | Real estate | 2025 |
| Debuglabs Ltd | Information & communication | 2020 |
| Decadence Beauty Boutique Limited | Other services | 2013 |
| Decopal Shop Ltd | Wholesale & retail | 2024 |
| DEL Duca Refridgeration Ltd | Wholesale & retail | 2024 |
| Deli Building Services Ltd | Construction | 2022 |
| Delight Energy Solution Ltd | Professional & scientific | 2025 |
| Deluxe Nails 31 Ltd | Other services | 2026 |
| Demas Courier Ltd | Transport & logistics | 2023 |
| Denas Management Solutions Limited | Administrative & support | 2011 |
| Denish Solutions Ltd | Wholesale & retail | 2025 |
| Dent Enterprises Limited | Wholesale & retail | 2016 |
| Dent's Transport Ltd | Transport & logistics | 2025 |
| Derin UK North Limited | Hospitality | 2013 |
| Dessert Isle Crowle Ltd | Hospitality | 2025 |
| Detection Solutions Limited | Construction | 2004 |
| Detora Ltd | Wholesale & retail | 2024 |
| DG Cargo Ltd | Transport & logistics | 2016 |