| Devidu Retail Limited | Wholesale & retail | 2022 |
| Devt Limited | Information & communication | 1998 |
| Dewan Developments Ltd | Financial services | 2024 |
| Dewitrabin Ltd | Wholesale & retail | 2026 |
| Dewys Ltd | Construction | 2026 |
| Dexters Build Ltd | Construction | 2026 |
| Dexters Roof Care Ltd | Construction | 2026 |
| Dfinity Group Ltd | Professional & scientific | 2026 |
| DFL (UK) Systems Limited | Hospitality | 1994 |
| DG Andrusiac Ltd | Construction | 2023 |
| DG Clean Limited | Administrative & support | 2026 |
| DG Decoration Ltd | Construction | 2021 |
| Dgwa Consultancy Ltd | Professional & scientific | 2023 |
| DH Motor Factors Ltd | Wholesale & retail | 2024 |
| DH94 Studios Ltd | Information & communication | 2025 |
| DHN Consultants Limited | Professional & scientific | 2020 |
| Diamond Bar & Lounge Ltd | Hospitality | 2022 |
| Diamondbane Limited | Professional & scientific | 1999 |
| Diffable Limited | Administrative & support | 2020 |
| Digilane Logistic Ltd | Transport & logistics | 2017 |
| Digital Anchor Limited | Information & communication | 2025 |
| Digital Flourish Ltd | Information & communication | 2013 |
| Digital M Pro Limited | Manufacturing | 2019 |
| Digital Reflection Studios Ltd | Arts & recreation | 2020 |
| Dilam Group Limited | Wholesale & retail | 2025 |
| Diligency Limited | Financial services | 2015 |
| Dilruba Limited | Hospitality | 2025 |
| Dinca Doru Limited | Transport & logistics | 2018 |
| Dinca Marian Limited | Transport & logistics | 2024 |
| Dinmd Associates Ltd | Health & social care | 2015 |
| Dionne Manning @ Fitter Body Ladies Luton Ltd | Arts & recreation | 2022 |
| Direct 2 Keys Ltd | Transport & logistics | 2024 |
| Direct Cars (Bedford) Ltd | Transport & logistics | 2011 |
| Direct Cd's Limited | Manufacturing | 2002 |
| Direct Products Aylesbury Limited | Wholesale & retail | 2021 |
| Direct Water Coolers Limited | Extraterritorial | 2001 |
| Dirty Duck Holdings Limited | Hospitality | 2025 |
| DIS Drylining Ltd | Construction | 2018 |
| Disca Ltd | Construction | 2014 |
| Discover Tracking Ltd | Administrative & support | 2021 |
| Discovery Vacation Club Limited | Administrative & support | 2006 |
| Disifin Hygiene UK Ltd | Wholesale & retail | 2001 |
| Distal Point Limited | Health & social care | 2007 |
| Dive Gym Equipment Limited | Professional & scientific | 1994 |
| Diverse Screed and Resin Contractors Limited | Construction | 2014 |
| Diyapadma Consultancy Ltd | Information & communication | 2013 |
| Djcsewing Ltd | Manufacturing | 2016 |
| DJL Electrical Contractors Limited | Construction | 2010 |
| DJS4HIRE Limited | Arts & recreation | 2018 |
| DK General Building Ltd | Construction | 2023 |
| Dkdesigned Construction Ltd | Construction | 2021 |
| DKM Golf and Leisure Limited | Arts & recreation | 2014 |
| DL Taylored Trading Group Ltd | Real estate | 2024 |
| DL Travels and Tours Services International Ltd | Information & communication | 2023 |
| DLA Driving School Ltd | Education | 2020 |
| DLB Railway Signal & Design Installation Ltd | Construction | 2015 |
| DLG Auto Repair Limited | Wholesale & retail | 2014 |
| DLN Engineering Limited | Manufacturing | 2018 |
| DLR Fire Engineering Ltd | Construction | 2025 |
| DM Precision Surveying & Estimating Ltd | Construction | 2022 |
| DM Tech Consultants Limited | Information & communication | 2015 |
| DMC Plasterering Services Ltd | Construction | 2021 |
| Dmdt Ltd | Real estate | 2023 |
| DNA Clean Ltd | Administrative & support | 2022 |
| DNA Removals Ltd | Transport & logistics | 2022 |
| DNA Servicing Limited | Construction | 2022 |
| DND Properties Development Ltd | Real estate | 2018 |
| Dndbros Ltd | Real estate | 2025 |
| Dogs at Work Limited | Construction | 2011 |
| Dogtooth Sourcing Limited | Wholesale & retail | 2006 |
| Doire Transport Limited | Transport & logistics | 2016 |
| Dolittles Animal Training Limited | Other services | 2021 |
| Dollies Boutique Ltd | Other services | 2025 |
| Dolly Estate Group Limited | Real estate | 2025 |
| Dolly Legacy Holdings Limited | Financial services | 2025 |
| Dolmans Place Residents Limited | Households | 2003 |
| Domeki Sculptures Ltd | Wholesale & retail | 2025 |
| Dominion City Dunstable | Education | 2025 |
| Domlyt Ltd | Construction | 2025 |
| Domovo Properties Ltd | Real estate | 2025 |
| DON Baxy Transport Ltd | Transport & logistics | 2022 |
| DON Spirit Ltd | Real estate | 2026 |
| Donica Trans Ltd | Transport & logistics | 2025 |
| Donnell Electrical Contractors Limited | Construction | 2005 |
| Dorcan Limited | Hospitality | 2024 |
| Dorcess Ltd | Other services | 2016 |
| Doridge Limited | Hospitality | 2019 |
| Dorota Estates Ltd | Real estate | 2019 |
| Dothan Ltd. | Administrative & support | 2006 |
| Dove CFO Services Limited | Administrative & support | 2025 |
| Doviho Services Ltd | Administrative & support | 2021 |
| Down's Cafe Ltd | Hospitality | 2018 |
| Downs Car Sales Ltd | Wholesale & retail | 2017 |
| Downton Court Residents Association Limited | Real estate | 1983 |
| Doyle Developments & Sons Limited | Construction | 2023 |
| Doyle Homes Limited | Construction | 2018 |
| DP - DEX Ltd | Transport & logistics | 2024 |
| DPS Building Ltd | Construction | 2019 |
| DR Care Limited | Health & social care | 2022 |
| DR Drive Limited | Education | 2026 |