| Desai Family Partnership LLP | | 2018 |
| Design Dunker Ltd | Professional & scientific | 2020 |
| Design: Aesthetics Limited | Health & social care | 2007 |
| Desire Doors Ltd | Construction | 2024 |
| Detees Ltd | Real estate | 2017 |
| Devereux Developments Limited | Transport & logistics | 1977 |
| DG and MJ Associates Ltd | Professional & scientific | 2022 |
| DG Bond Limited | Mining & quarrying | 2021 |
| DGM Anaesthetics Limited | Health & social care | 2024 |
| DGM Management Consultants Limited | Professional & scientific | 2014 |
| DH Specialist Care Ltd | Health & social care | 2019 |
| DHE Management Limited | Households | 2021 |
| Dheeraj & Co Limited | Professional & scientific | 2012 |
| Diagnose.Codes Ltd | Wholesale & retail | 2025 |
| Dial Contractual Services Limited | Professional & scientific | 2022 |
| Diamond Devils Limited | Wholesale & retail | 2021 |
| Digital Software Technology Limited | Information & communication | 1996 |
| Digital Touch Agency Ltd | Professional & scientific | 2021 |
| Digitalshe Limited | Wholesale & retail | 2025 |
| Dilly's Digs Limited | Real estate | 2012 |
| Dilly's Digs Partnership LLP | | 2018 |
| Dinkies Swim School Limited | Arts & recreation | 2019 |
| Dipex Lettings and Management Limited | Real estate | 2012 |
| Direct Inter-Active Limited | Extraterritorial | 2011 |
| Direct Properties NE Ltd | Real estate | 2026 |
| Dispense-A-Vend Limited | Hospitality | 2008 |
| District 23 Billingham Limited | Administrative & support | 2016 |
| DJ Jointing Services Ltd | Construction | 2025 |
| DJC Merlin Ltd | Hospitality | 2020 |
| DJE Group Ltd | Education | 2017 |
| DJH Wynyard Limited | Construction | 2017 |
| DJS Aviation Ltd | Wholesale & retail | 2025 |
| DJS Process Consulting Limited | Professional & scientific | 2015 |
| Djwalker Inspection Services Ltd | Professional & scientific | 2025 |
| DK Electrical NE Ltd | Construction | 2026 |
| DLP Automation Ltd | Professional & scientific | 2022 |
| DMB Structural Analysis Limited | Professional & scientific | 2020 |
| Dmck Lifting Ltd | Construction | 2017 |
| DML North Ltd | Other services | 2017 |
| DMS Staffing and Recruitment (North East) Ltd | Health & social care | 2026 |
| DN Wind Tech Ltd | Manufacturing | 2024 |
| Dobson Family Holdings Ltd | Real estate | 2021 |
| Dobson Family Partnership LLP | | 2021 |
| Dodd Family Holdings Ltd | Real estate | 2019 |
| Dodd Family Partnership LLP | | 2019 |
| Dodgson Mechanical Services Ltd | Wholesale & retail | 2019 |
| Doggie Days Ltd | Other services | 2019 |
| Dolezy Family Partnership LLP | | 2023 |
| Dolfi Professional Limited | Transport & logistics | 2019 |
| Donnington Properties Limited | Real estate | 2014 |
| Doornbos Equipment Limited | Extraterritorial | 2017 |
| Dougall Family Partnership LLP | | 2018 |
| Downey Family Partnership LLP | | 2019 |
| Downey Homes Limited | Construction | 2017 |
| Doyle and Simpson LLP | | 2018 |
| Doyle Family Partnership LLP | | 2018 |
| DP Consultancy(North East) Limited | Education | 2008 |
| Dpcj Ltd | Health & social care | 2025 |
| DPD Property Ltd | Real estate | 2020 |
| DPR (UK) Limited | Professional & scientific | 2014 |
| DPT Uk/Euro Ltd | Arts & recreation | 2014 |
| DR Botan and Ojechi Ltd | Hospitality | 2024 |
| DR Investments Holding Ltd | Financial services | 2023 |
| Dragon Corp Limited | Professional & scientific | 2019 |
| Dragon Properties (NE) Limited | Real estate | 2022 |
| Dream Property Solutions Limited | Real estate | 2013 |
| Driver Project Services Limited | Professional & scientific | 1993 |
| Driver Safety Solutions Limited | Wholesale & retail | 2026 |
| Driving Success Limited | Professional & scientific | 2010 |
| DRK Compliance and Advisory Limited | Professional & scientific | 2019 |
| Drmegmohan Limited | Health & social care | 2024 |
| Drumandbells Limited | Hospitality | 2016 |
| Drummonds Estate Agents Limited | Real estate | 2009 |
| Drury Housing Ltd | Real estate | 2025 |
| DTW Education Ltd | Education | 2022 |
| DTZ Holdings Ltd | Real estate | 2022 |
| DU66 Ltd | Construction | 2026 |
| Dumbbell Central Limited | Wholesale & retail | 2024 |
| Dunbar Consultants Ltd | Professional & scientific | 2013 |
| Duratemp Ltd | Construction | 2025 |
| Durham City Taxis Limited | Transport & logistics | 2023 |
| Durnion Consultancy Holdings Limited | Other services | 2016 |
| Durnion Consultancy Limited | Manufacturing | 2007 |
| Dutch Garden Centre (Hartlepool) Limited | Wholesale & retail | 2022 |
| DW Property Investments Limited | Real estate | 2018 |
| DWM Mechanical Services Ltd | Professional & scientific | 2025 |
| DWW Asbestos Removal Services Limited | Water & waste | 2019 |
| E Eureka Limited | Administrative & support | 2006 |
| E M Leisure Limited | Hospitality | 2003 |
| E Okoli WP Ltd | Administrative & support | 2024 |
| E&A Teesside Dog Boarding Services Ltd | Other services | 2025 |
| E&H Transport Ltd | Transport & logistics | 2023 |
| E-Vision Concept Holdings Limited | Real estate | 2016 |
| E-Vision Concept Limited | Construction | 2006 |
| Eagle Professional Healthcare Ltd | Health & social care | 2022 |
| Eame Investments Limited | Professional & scientific | 1971 |
| Earle Anthony LLP | | 2018 |
| Eason Family Partnership LLP | | 2021 |
| East of England Productions Ltd | Arts & recreation | 2022 |
| Eastern Way Investments Company Ltd | Real estate | 2025 |