| Cybercenter Limited | Information & communication | 2025 |
| Cybercity Limited | Other services | 2017 |
| Cybercraft Limited | Information & communication | 2025 |
| Cyberdyne Holdings Limited | Real estate | 2017 |
| Cybereye Aviation Security Limited | Administrative & support | 2022 |
| Cyberfu Ltd | Information & communication | 2016 |
| Cyberprae Limited | Information & communication | 2010 |
| Cybersec Compliance Ltd | Information & communication | 2026 |
| Cybertag Consulting Ltd | Information & communication | 2018 |
| Cybsec Consultancy Limited | Information & communication | 2025 |
| Cyganaideddesign Limited | Professional & scientific | 2024 |
| Cygnit Support Services Ltd | Information & communication | 2009 |
| Cygnus Limited | Professional & scientific | 2016 |
| Cylgen Ltd | Administrative & support | 2015 |
| Cynergistic Technologies Limited | Wholesale & retail | 2006 |
| Cyntex IT Solutions Limited | Information & communication | 2014 |
| CYP Health Ltd | Professional & scientific | 2024 |
| Cyprusphere Ltd | Real estate | 2025 |
| Cyrisq Ltd | Information & communication | 2024 |
| Cyrus Consulting Civil and Structural Engineers Ltd | Professional & scientific | 2017 |
| Cyrwood Limited | Real estate | 2021 |
| Cywift Limited | Wholesale & retail | 2023 |
| Czakan Ltd | Construction | 2014 |
| CZM Properties LLP | | 2021 |
| Czyzyk Ltd | Transport & logistics | 2015 |
| D & E Builders and Developers Ltd | Construction | 2022 |
| D & E Pro Ltd | Professional & scientific | 2021 |
| D & I Solutions Limited | Transport & logistics | 2024 |
| D & I Window Cleaning (MK) Ltd | Administrative & support | 2006 |
| D & M Global Ltd | Real estate | 2025 |
| D & M Sparks Ltd | Construction | 2023 |
| D a C GAS and Heating Engineers Ltd | Construction | 2002 |
| D and J Properties MK Ltd | Real estate | 2020 |
| D and R Hair Limited | Other services | 2018 |
| D Armonas Limited | Wholesale & retail | 2023 |
| D B Murray Limited | Construction | 2022 |
| D Bride Investments Limited | Financial services | 2025 |
| D Bride Limited | Information & communication | 2023 |
| D C & Sons Limited | Construction | 2010 |
| D Composites Ltd | Professional & scientific | 2025 |
| D Coyle & SON Ltd | Manufacturing | 2023 |
| D E P Fabrications Limited | Manufacturing | 1992 |
| D F & SON Plumbing and Heating Limited | Construction | 2021 |
| D F Crash Repairs Limited | Wholesale & retail | 1996 |
| D G S Construction Limited | Construction | 1997 |
| D Haynes Roofing Limited | Construction | 2017 |
| D Hibbit Limited | Information & communication | 2024 |
| D I P Mobile Car Wash & Valeting Limited | Administrative & support | 2021 |
| D I S Networks Ltd | Information & communication | 2010 |
| D J Composites Limited | Wholesale & retail | 2013 |
| D J S Urology Limited | Other services | 2012 |
| D J Sorrell Electrical Contractor Limited | Construction | 2005 |
| D M Enforcement Ltd | Administrative & support | 2017 |
| D M F Car Repairs Limited | Wholesale & retail | 2015 |
| D M Lloyd Limited | Other services | 2007 |
| D Macdonald Consulting Services Ltd | Professional & scientific | 2022 |
| D R G Building Services Limited | Construction | 2013 |
| D R Norman Ltd | Information & communication | 2016 |
| D Robinson Roofing Services Limited | Construction | 2020 |
| D Thompson Kitchens Limited | Manufacturing | 2013 |
| D&A Commercial Cleaning Ltd | Information & communication | 2020 |
| D&A COX Ltd | Construction | 2022 |
| D&E Design Limited | Construction | 2024 |
| D&G Beauty Limited | Other services | 2026 |
| D&G Movers Ltd | Transport & logistics | 2026 |
| D&G=MC2 Limited | Real estate | 2017 |
| D&I Invest Ltd | Real estate | 2024 |
| D&I Logistics Ltd | Transport & logistics | 2022 |
| D&I Urban Engineering Ltd | Construction | 2017 |
| D&J Capital Ltd | Wholesale & retail | 2021 |
| D&J Moves Limited | Administrative & support | 2020 |
| D&L Electrical & Fibre Ltd | Construction | 2025 |
| D&M Beauty Salon Ltd | Other services | 2024 |
| D&M Luxury Homes Ltd | Real estate | 2024 |
| D&N Accountancy Ltd | Professional & scientific | 2021 |
| D&R Home Cleaning Limited | Transport & logistics | 2025 |
| D&S Property MK Ltd | Real estate | 2026 |
| D&S Thorax Limited | Health & social care | 2025 |
| D&T Advisory Ltd | Financial services | 2025 |
| D&T Home Care Ltd | Health & social care | 2023 |
| D&T Investments Limited | Water & waste | 2007 |
| D&W Locks Ltd | Other services | 2019 |
| D'Austin Residential Developments Hayes Ltd | Real estate | 2021 |
| D'Rose Development Consultancy Ltd | Professional & scientific | 2020 |
| D'Vision Ltd | Construction | 2020 |
| D-Locales Ltd | Real estate | 2023 |
| D-Roadmap Ltd | Information & communication | 2023 |
| D-Tech AZ Ltd | Wholesale & retail | 2023 |
| D. G. L. Scott Limited | Financial services | 2010 |
| D.B. Standing & SON Ltd | Mining & quarrying | 2002 |
| D.C Property Finance Limited | Financial services | 2022 |
| D.C. Hall Limited | Manufacturing | 1964 |
| D.D.Costea Ltd | Construction | 2019 |
| D.G. Finance Limited | Financial services | 1987 |
| D.J.Howard Limited | Health & social care | 2011 |
| D.M.S. International Limited | Transport & logistics | 1976 |
| D.Macintyre & SON Limited | Professional & scientific | 1955 |
| D.O.G Roofing Limited | Construction | 2024 |
| D.R.Perry & Co.(Bushley)Limited | Agriculture & fishing | 1963 |
| D.S.M.M. Property Services Limited | Real estate | 1996 |