| D C Performance Limited | Wholesale & retail | 2010 |
| D C Renovations Ltd | Construction | 2019 |
| D C Screeding and Preparation Limited | Construction | 2019 |
| D G Church Limited | Financial services | 2024 |
| D Gilbert Carpentry Ltd | Manufacturing | 2022 |
| D J L Prodec Limited | Construction | 2009 |
| D J Moyse Surfacing Ltd | Administrative & support | 2014 |
| D K Sports Management Limited | Arts & recreation | 2010 |
| D K Ward Ltd | Administrative & support | 2014 |
| D Lemas Ltd | Transport & logistics | 2017 |
| D M Ferns Ltd | Other services | 2023 |
| D M Long & Sons Limited | Construction | 2004 |
| D Macas Ltd | Transport & logistics | 2019 |
| D P Heating and Plumbing Limited | Administrative & support | 2017 |
| D Richards Consulting Limited | Professional & scientific | 2020 |
| D T E Maintenance Ltd | Administrative & support | 2024 |
| D W Adams Ltd | Construction | 2011 |
| D W O'Dowd Limited | Construction | 2009 |
| D&A Finch Services Limited | Hospitality | 2014 |
| D&A Pro Ltd | Construction | 2024 |
| D&B Balconies Limited | Construction | 2024 |
| D&C 3PLUMBING and Heating Ltd | Construction | 2026 |
| D&C East Transport Ltd | Transport & logistics | 2021 |
| D&C Plumbing Ltd | Construction | 2019 |
| D&D Drylining and Plastering Ltd | Construction | 2016 |
| D&D Loyal Construction Ltd | Construction | 2021 |
| D&D Stancu Ltd | Transport & logistics | 2022 |
| D&H Auto Services and Repairs Ltd | Wholesale & retail | 2024 |
| D&L Green Holdings Limited | Financial services | 2026 |
| D&N Electrical (East Anglia) Ltd | Construction | 2011 |
| D&R Restaurant Group Limited | Hospitality | 2022 |
| D&S Transport Ltd | Transport & logistics | 2025 |
| D&X Auto Sales Ltd | Wholesale & retail | 2023 |
| D'Sauce Afro-Kitchen Ltd | Hospitality | 2020 |
| D'Z Burgers Ltd | Hospitality | 2013 |
| D-Signs (Suffolk) Limited | Manufacturing | 2012 |
| D. B. Health & Fitness Limited | Health & social care | 2005 |
| D. J. B. Logistics Limited | Administrative & support | 2005 |
| D. Wills Physiotherapy Limited | Health & social care | 2012 |
| D.A LAB Ltd | Professional & scientific | 2025 |
| D.A.B Plant and Vehicle Repairs Ltd | Wholesale & retail | 2014 |
| D.C. Home Maintenance Limited | Construction | 2012 |
| D.G. Property Development Limited | Construction | 2003 |
| D.J. Spall (Recycling) Limited | Other services | 1995 |
| D.J.D Plumbing and Heating Ltd | Construction | 2007 |
| D.M.C Transport Ltd | Transport & logistics | 2021 |
| D.P.M. Mechanical and Electrical Engineers Limited | Wholesale & retail | 2003 |
| D.R. Munson Limited | Transport & logistics | 1987 |
| D.S. Fasteners Limited | Manufacturing | 1976 |
| D360 Design Limited | Information & communication | 2011 |
| D7 Construction Ltd | Construction | 2024 |
| DA Accountancy Solutions Ltd | Professional & scientific | 2025 |
| DA Costa Plumbing and Heating Limited | Other services | 2017 |
| DA IT Solutions Limited | Information & communication | 2023 |
| Daaav Ltd | Transport & logistics | 2020 |
| Daas Accounting Services Ltd | Professional & scientific | 2011 |
| DAB Associates (Stanton) Ltd | Administrative & support | 2022 |
| DAB Civil Engineering Ltd | Construction | 2006 |
| DAB Infrastructure Services Ltd | Construction | 2007 |
| DAB Scaffolding & Roofing Limited | Construction | 2006 |
| Dabo US Ltd | Information & communication | 2013 |
| Dac-R Consultancy Limited | Professional & scientific | 2024 |
| Daca Limited | Administrative & support | 2012 |
| Dachman Group Ltd | Transport & logistics | 2020 |
| Daco Marketing Limited | Professional & scientific | 1994 |
| Dadel Energy Services Limited | Construction | 2025 |
| Daemmon Reeve Consulting Limited | Professional & scientific | 2025 |
| Dafren Ltd | Professional & scientific | 2025 |
| Dagher Ltd | Professional & scientific | 2021 |
| Dailixor Readysheets Ltd | Manufacturing | 2026 |
| Daily Fresh Ipswich Ltd | Wholesale & retail | 2022 |
| Dairy Close (Anglia) Management Company Limited | Administrative & support | 2017 |
| Daisha Health Limited | Health & social care | 2020 |
| Daisy Russell Designs Limited | Professional & scientific | 2021 |
| Daisylewishair Ltd | Other services | 2024 |
| Daisyshoots Ltd | Administrative & support | 2025 |
| Dale Electrical Limited | Construction | 2001 |
| Dale Hall Group Limited | Real estate | 2025 |
| Dales Ipswich (Management) Limited | Real estate | 2003 |
| Dales Road M.O.T Centre Ltd | Wholesale & retail | 2024 |
| Dalia's Beauty Ltd | Other services | 2024 |
| Dalmag Limited | Manufacturing | 1993 |
| Dalmally Asset Investment Limited | Hospitality | 2016 |
| Damally Management Limited | Hospitality | 2016 |
| Damant Wealth Management Limited | Financial services | 2014 |
| Damco (Investment Solutions) Limited | Financial services | 2026 |
| Damgidi Bridals Ltd | Manufacturing | 2024 |
| Damivisuals Ltd | Information & communication | 2025 |
| DAN Pro Building Ltd | Construction | 2025 |
| DAN Will LLP | | 2010 |
| Danautomation Limited | Information & communication | 2024 |
| Dance & Dean Holdings Limited | Financial services | 2024 |
| Dance & Dean Limited | Construction | 2000 |
| Dance Afloat Limited | Professional & scientific | 2017 |
| Dance East | Education | 1997 |
| Dance Property Partnership Limited | Real estate | 2024 |
| Danceeast Enterprises Limited | Arts & recreation | 2010 |
| Danceeats Limited | Hospitality | 2009 |
| Dancing Text Ltd | Information & communication | 2010 |
| Dand Transport Ltd | Transport & logistics | 2022 |