| Cuppers Journey Limited | Wholesale & retail | 2024 |
| Curlew Accounting Ltd | Professional & scientific | 2019 |
| Currency Publications Limited | Information & communication | 2002 |
| Currie & Currie LLP | | 2008 |
| Cuthberts Independent Trading Ltd | Wholesale & retail | 2019 |
| Cybernorth CIC | Other services | 2023 |
| Cycleplot Ltd | Professional & scientific | 2023 |
| D and M Legal Services Limited | Professional & scientific | 2014 |
| D Carmichael Agricultural Valuers Ltd | Real estate | 2009 |
| D. & S. Denham & SON Limited | Transport & logistics | 2006 |
| D.J. & M. Parry Limited | Agriculture & fishing | 1970 |
| D3 Associates Ltd | Professional & scientific | 2009 |
| DAA North East Limited | Administrative & support | 2020 |
| Daisy Cottages Northumberland Limited | Real estate | 2025 |
| Daisychain Dairies Ltd | Wholesale & retail | 2023 |
| Dale Holidays Limited | Real estate | 2019 |
| Dales Agri Sales Agency Limited | Administrative & support | 2009 |
| Dalkin Digital Agility Limited | Information & communication | 2023 |
| Dancer Developments Limited | Construction | 2016 |
| Daniel Armstrong Limited | Professional & scientific | 2017 |
| Daniels London Limited | Manufacturing | 2010 |
| Dark RE Limited | Real estate | 2026 |
| Darren Richmond Ltd | Information & communication | 2015 |
| Daunt Resolution Services Ltd | Professional & scientific | 2020 |
| David Dixon Limited | Manufacturing | 2013 |
| David Henderson Tractors Limited | Wholesale & retail | 2009 |
| David Jones Services Limited | Construction | 2015 |
| David Mackenzie Mortgages Ltd | Financial services | 2025 |
| David Mullins Construction Consultancy Ltd | Construction | 2014 |
| David Robinson Nurseries Limited | Wholesale & retail | 1985 |
| David S Ferguson Limited | Construction | 2011 |
| Day Interior Design Ltd | Professional & scientific | 2025 |
| DC Custom Builds Ltd | Construction | 2025 |
| Debbi's Doodles CIC | Education | 2023 |
| Deek at US Limited | Wholesale & retail | 2025 |
| Defence Photography Limited | Arts & recreation | 2014 |
| Defence Services Limited | Professional & scientific | 2014 |
| Delegate Investments Limited | Arts & recreation | 2019 |
| Delivery Focus Limited | Information & communication | 2010 |
| Dene House and Court Management Company Ltd | Households | 2014 |
| Deneholme Care Centre Ltd | Health & social care | 2021 |
| Dent Holdings Limited | Financial services | 2022 |
| Denton Estates Limited | Real estate | 1987 |
| Derek Todd Associates Ltd | Administrative & support | 2017 |
| Detilly Ltd | Professional & scientific | 2021 |
| Diane Makepeace Photography Limited | Professional & scientific | 2021 |
| Dilbeck Remediation & Conduct Ltd | Real estate | 2017 |
| DJ & JW Holdings Limited | Financial services | 2022 |
| DJ & SJ Renewables Limited | Agriculture & fishing | 2013 |
| DJS Offshore Ltd | Energy | 2021 |
| DM Designers Ltd | Information & communication | 2016 |
| DMP Building Solutions Limited | Construction | 2024 |
| DNJ NDT Ltd | Professional & scientific | 2023 |
| DO IT Safely Limited | Other services | 2015 |
| Dodwell Brothers Limited | Construction | 1996 |
| Dodwell Cleaning Services Ltd | Administrative & support | 2025 |
| Donkleywood Farm Limited | Agriculture & fishing | 2008 |
| Doodles Tech Ltd | Information & communication | 2024 |
| Dose of Reality Limited | Professional & scientific | 2025 |
| Dovetail North East Ltd | Health & social care | 2025 |
| Dovewoodwork Ltd | Manufacturing | 2022 |
| Down N OUT Limited | Professional & scientific | 2011 |
| Down to Earth Direct Limited | Extraterritorial | 2020 |
| DPR Inspection Services Limited | Professional & scientific | 2012 |
| Dramatic Exit Limited | Information & communication | 2024 |
| DRD Property Maintenance Ltd | Administrative & support | 2018 |
| Drift Creative Design LLP | | 2024 |
| Dryside Glamping Pods Limited | Hospitality | 2018 |
| DT Group Ltd. | Information & communication | 2016 |
| Dulabhai Ltd | Hospitality | 2017 |
| DW Express Ltd | Transport & logistics | 2026 |
| E. Dodd & Sons Ltd | Agriculture & fishing | 2012 |
| E.T Fitness & Therapy Ltd | Arts & recreation | 2023 |
| E3 R&D Limited | Professional & scientific | 2014 |
| Eager Property Solutions Ltd | Real estate | 2020 |
| East of the Sea Ltd | Wholesale & retail | 2023 |
| Eastside House Ltd | Wholesale & retail | 2025 |
| Easy Hire North East Limited | Administrative & support | 2015 |
| Easy-Company Ltd | Manufacturing | 2022 |
| EAT Sleep GIN Repeat Limited | Hospitality | 2017 |
| ECC Engineering Ltd | Professional & scientific | 2024 |
| Eclectic Systems Professionals Limited | Real estate | 1991 |
| Ecled Limited | Professional & scientific | 2026 |
| ECM Motors Ltd | Wholesale & retail | 2019 |
| Eco Aftercare UK Ltd | Other services | 2014 |
| Ecocabs Limited | Wholesale & retail | 2007 |
| Edricorp Technologies Limited | Information & communication | 2021 |
| Educate Yorkshire Ltd | Education | 2016 |
| Egger (UK) Limited | Manufacturing | 1993 |
| Egger Forestry Limited | Agriculture & fishing | 1993 |
| Egger USA Investment Limited | Administrative & support | 2018 |
| Eggs-Port Limited | Agriculture & fishing | 1994 |
| Eilansgate House Management Company Limited | Households | 2006 |
| Electratest Northern Limited | Construction | 1996 |
| Electron Wheels Limited | Wholesale & retail | 2019 |
| ELITE3D Ltd | Professional & scientific | 2024 |
| Ellison & Co. | Real estate | 1978 |
| Ellkew Holdings Ltd | Financial services | 2023 |
| ELM Pheasantries Limited | Agriculture & fishing | 2018 |
| Elvaston Forest Ltd | Real estate | 2025 |