| DB Digital (UK) Ltd | Information & communication | 2024 |
| DB5 Consultancy Limited | Professional & scientific | 2023 |
| Dbank Data Ltd | Professional & scientific | 2023 |
| DBD Driveways & Patios Ltd | Administrative & support | 2020 |
| Dbfy Education Ltd | Education | 2022 |
| DC Research Ltd. | Administrative & support | 2008 |
| DCL Groundworks Limited | Construction | 2024 |
| DCT Events Ltd | Professional & scientific | 2023 |
| DCT Trading Limited | Agriculture & fishing | 2019 |
| DDRM3 Limited | Construction | 2017 |
| DE Ville Taverns Limited | Hospitality | 2005 |
| De-Pak Ltd | Professional & scientific | 2022 |
| Dean Johnstone Interiors Limited | Construction | 2020 |
| Dearling Construction Limited | Construction | 2014 |
| Deathbed Ltd | Information & communication | 2018 |
| Debrose Group Limited | Health & social care | 2025 |
| Debt Plan Ltd | Professional & scientific | 2023 |
| Debts-In Limited | Administrative & support | 2011 |
| Declan Bowman Holdings Limited | Financial services | 2025 |
| Decs Developments Limited | Real estate | 2002 |
| Deer Nora Property Group Limited | Real estate | 2024 |
| Deer Park Property Limited | Real estate | 2022 |
| Deercroft Homes Limited | Construction | 2015 |
| Deeside Communications Limited | Information & communication | 2014 |
| Deesnaturecare Limited | Health & social care | 2025 |
| Deezee Limited | Health & social care | 2003 |
| Dejavu Cumbria Ltd | Hospitality | 2019 |
| Delicatessen Pysio Ltd | Wholesale & retail | 2009 |
| Deller People Ltd | Administrative & support | 2025 |
| Delta Contracting Ltd | Construction | 2019 |
| Dennis Waggott Building Contractor Limited | Construction | 1999 |
| Dens, Daisies & Discoveries CIC | Education | 2024 |
| Dentco Carlisle Ltd | Wholesale & retail | 2024 |
| Denton Developments Limited | Construction | 2016 |
| Denton Memorials Ltd | Manufacturing | 2021 |
| Denton Properties (Carlisle) Limited | Real estate | 2016 |
| Denton Store Ltd | Wholesale & retail | 2025 |
| Denton Vapespot Ltd | Wholesale & retail | 2026 |
| Denton Wharf Marine Services Limited | Energy | 2024 |
| Dentonside Geotechnical Consultants Limited | Professional & scientific | 2021 |
| DEO Volente Singers CIC | Education | 2013 |
| Dermalab Limited | Extraterritorial | 2009 |
| Derwent Forest Management Company Limited | Real estate | 2018 |
| Derwent Services Limited | Professional & scientific | 2004 |
| Derwentcourt Limited | Wholesale & retail | 2000 |
| Derwyn Systems Limited | Information & communication | 2022 |
| Des-Cad Limited | Professional & scientific | 1997 |
| Design Allison Ltd | Professional & scientific | 2023 |
| Design Interiors Cumbria Limited | Professional & scientific | 2023 |
| Designer Stone Shower Trays Ltd | Wholesale & retail | 2018 |
| DEVELOP10 Ltd | Households | 2019 |
| Developmentco Limited | Real estate | 2007 |
| Devine Music Holdings Limited | Financial services | 2025 |
| Devine Music Limited | Professional & scientific | 2013 |
| Devoaim Limited | Wholesale & retail | 1984 |
| Devonshire House Denture Solutions Limited | Health & social care | 2011 |
| Devonshire Lodge Limited | Real estate | 2014 |
| Devonshire Maintenance Ltd | Construction | 2025 |
| Devonshire Security Limited | Administrative & support | 2025 |
| Dexter Cattle Society(The) | Agriculture & fishing | 1899 |
| DG Deliveries Limited | Transport & logistics | 2018 |
| DG Direct Ltd | Construction | 2015 |
| DGT Consultants Limited | Professional & scientific | 2006 |
| DH Groundworks (Cumbria) Ltd | Construction | 2019 |
| Dhalech Associates Ltd | Professional & scientific | 2024 |
| Dhaulagiri Security Limited | Administrative & support | 2021 |
| Diabetes Care Trust (Abcd) Limited | Administrative & support | 2010 |
| Diamond Gleam Cleaning Services Ltd | Administrative & support | 2025 |
| Dicano Ltd | Wholesale & retail | 2021 |
| Dick Brothers Forestry Limited | Agriculture & fishing | 2018 |
| Dick Thompson & Co (Cumbria) Limited | Construction | 1984 |
| Dickinson Haulage Ltd | Transport & logistics | 2016 |
| Dickinson's Joinery Limited | Construction | 2022 |
| Dickman Fencing & Paving Limited | Construction | 2018 |
| Dickson Holdings Limited | Real estate | 2016 |
| Digital Agile Solutions Ltd | Information & communication | 2023 |
| Digital BEE Marketing Ltd | Professional & scientific | 2010 |
| Digital Orthodontic Solutions Ltd | Manufacturing | 2016 |
| Digital Photo Express Carlisle Limited | Wholesale & retail | 2012 |
| Digivision Ltd | Information & communication | 2021 |
| Dima Holdings Limited | Administrative & support | 2019 |
| Dinger Cars Ltd | Wholesale & retail | 2025 |
| Dioka Limited | Real estate | 2026 |
| Direct Drainage and Developments Ltd | Water & waste | 2025 |
| Disdow Farm Bespoke Holidays Limited | Hospitality | 2022 |
| Distington Motor Trade Ltd | Wholesale & retail | 2024 |
| Divine Delivery Limited | Transport & logistics | 2025 |
| Dixon Grace Recruitment Limited | Administrative & support | 2009 |
| DJF Logistics Ltd | Transport & logistics | 2021 |
| DJK Civil Engineering Limited | Construction | 2019 |
| DJP Building Services Cumbria Ltd | Construction | 2022 |
| DJP Property Management and Lettings Ltd | Real estate | 2023 |
| Dker Ltd | Hospitality | 2025 |
| DKP Applications Limited | Professional & scientific | 2025 |
| DL Mortgage Services Limited | Professional & scientific | 2013 |
| DM Solutions Plumbing & Heating Ltd | Construction | 2018 |
| Dmack Ltd | Extraterritorial | 2024 |
| DMB Building Ltd | Construction | 2019 |
| DMC Deliveries Ltd | Transport & logistics | 2023 |
| DMR Removals Ltd | Transport & logistics | 2022 |