| Crowdventure (Darwin ST) Limited | Construction | 2020 |
| Crowdventure (Dunbar) Limited | Construction | 2020 |
| Crowdventure (Grayshott) Limited | Construction | 2021 |
| Crowdventure (the Manse) Limited | Construction | 2020 |
| Crown Home Care Limited | Health & social care | 2012 |
| Crystal Finishes Ltd | Administrative & support | 2018 |
| CS2 Consultancy Ltd | Administrative & support | 2022 |
| CT Floors Limited | Construction | 2013 |
| CT Performance Consulting Ltd | Professional & scientific | 2025 |
| CTS (Corby) Limited | Manufacturing | 2010 |
| Cube Sport Limited | Arts & recreation | 2021 |
| Culinary Concepts (London) Limited | Wholesale & retail | 2004 |
| Cultural Capitalism Ltd | Information & communication | 2017 |
| Cushty! Renovations Ltd | Construction | 2018 |
| CWQ Ltd | Professional & scientific | 2025 |
| Cypher Associates Ltd | Professional & scientific | 2025 |
| D & L Accounting Limited | Professional & scientific | 2018 |
| D & T Automotive Ltd | Wholesale & retail | 2022 |
| D&J Aesthetics Clinics (Basingstoke) Limited | Health & social care | 2025 |
| D&J Aesthetics Clinics Ltd | Health & social care | 2019 |
| D. H. Water Gardens Limited | Construction | 1988 |
| D.G. Spectro OIL Analysis Company Limited | Transport & logistics | 1980 |
| D2D2 Ltd | Health & social care | 2026 |
| Daisy's Tearoom Ltd | Hospitality | 2012 |
| Dalphy Construction Limited | Manufacturing | 2015 |
| Dalphy Developments Limited | Real estate | 2018 |
| Damac Ventures Limited | Construction | 2003 |
| Damales Ltd | Information & communication | 2021 |
| Dame Martina Consultancy Ltd | Professional & scientific | 2022 |
| Dane.Ly (Health Technologies) Ltd | Information & communication | 2018 |
| Dano Props Limited | Information & communication | 2015 |
| Dark Artistry Ltd | Professional & scientific | 2023 |
| Dark Horse Songs Limited | Information & communication | 2011 |
| Dark Matter Group Ltd | Professional & scientific | 2019 |
| Datafit Limited | Information & communication | 2022 |
| Dave Smith Scaffolding Ltd | Construction | 2010 |
| David James of London Limited | Transport & logistics | 1995 |
| David Simpson Consultancy Limited | Professional & scientific | 2017 |
| Davies Environmental Consultants Limited | Professional & scientific | 2008 |
| Davison Consultants Limited | Professional & scientific | 2006 |
| Dazzanet Limited | Arts & recreation | 2023 |
| DCM Electrical Limited | Professional & scientific | 2008 |
| Dcnet Ltd | Information & communication | 2024 |
| DDN Limited | Water & waste | 2007 |
| Dealer Exchange Limited | Information & communication | 2024 |
| Debonair Coach Travel Limited | Administrative & support | 2024 |
| Deborah Smith Children's Occupational Therapy Limited | Health & social care | 2012 |
| Decandia Limited | Professional & scientific | 2014 |
| Decarbonize Ltd | Professional & scientific | 2008 |
| Deep Spark Limited | Water & waste | 2017 |
| Defence Contractor Management and Operations Limited | Public administration | 1998 |
| Degrees C Environmental Limited | Construction | 2013 |
| Delightand Ltd | Professional & scientific | 2022 |
| Dental Design Products Limited | Information & communication | 2000 |
| Devmod Ltd | Transport & logistics | 2020 |
| Devonmill (London) Ltd | Wholesale & retail | 2003 |
| Dewberry Ltd | Information & communication | 2007 |
| DGK Flooring Limited | Construction | 2013 |
| DGS Accounting Services Ltd. | Professional & scientific | 2006 |
| DH Horticultural Developments Limited | Agriculture & fishing | 2017 |
| Diamond Mind Executive Coaching & Training Ltd | Professional & scientific | 2021 |
| Digital Automotive Solutions Ltd | Wholesale & retail | 2014 |
| Digital Design Ltd | Information & communication | 2005 |
| Digital Evaluation and Transformation Ltd | Professional & scientific | 2013 |
| Digital Nerve Ltd | Information & communication | 2000 |
| Dignity Pet Crematorium Limited | Professional & scientific | 2001 |
| Discount Haven 247 Ltd | Wholesale & retail | 2022 |
| Discovery Energy UK Acquisition Limited | Financial services | 2023 |
| Discovery Energy UK Holding Limited | Financial services | 2023 |
| Dista Products Limited | Manufacturing | 1962 |
| Distribution Zone Limited | Wholesale & retail | 2007 |
| Divida Solutions Ltd | Administrative & support | 2024 |
| DIY Aggregates Limited | Wholesale & retail | 2006 |
| DJB Plumbing Services Ltd | Construction | 2011 |
| DJB Property Services and Maintenance Ltd | Construction | 2026 |
| DKA Gardening Services Ltd | Administrative & support | 2026 |
| Dkcs Holdings Ltd | Construction | 2025 |
| DO Business Services Limited | Professional & scientific | 2016 |
| DO Estates Ltd | Real estate | 2026 |
| Dodds Healthcare Management & Consulting Ltd | Professional & scientific | 2004 |
| Dream View Group Ltd | Construction | 2026 |
| Dream View Homes Ltd | Construction | 2024 |
| Dream View Homes Marwell Ltd | Construction | 2025 |
| Dreamtek Limited | Administrative & support | 2001 |
| Dssb Ltd | Information & communication | 2015 |
| DTE Electrical & Property Solutions Ltd | Construction | 2022 |
| Duffy Law LLP | | 2026 |
| Duty Crew Limited | Education | 2021 |
| Dwane Construction Limited | Construction | 2023 |
| E&S Professional Services Ltd | Professional & scientific | 2024 |
| E.F.E. Services Limited | Information & communication | 2005 |
| E.S. Lighting Hire Limited | Administrative & support | 2007 |
| Eagle and Mane Limited | Wholesale & retail | 2022 |
| EBS Marketing Ltd | Administrative & support | 2010 |
| Echopassive Limited | Professional & scientific | 1988 |
| Eco Clean Cycle Ltd | Manufacturing | 2023 |
| Edmi Europe Limited | Wholesale & retail | 2011 |
| Edney & Daughters Ltd | Real estate | 2023 |
| Education in Motion UK Limited | Education | 2022 |
| Eeffaa Ltd | Real estate | 2019 |