| Dawson Media Direct Limited | Wholesale & retail | 2009 |
| Dawson Media Services Limited | Professional & scientific | 2009 |
| Dawson's Tree & Gardening Services Ltd | Agriculture & fishing | 2025 |
| Daxaplus Limited | Wholesale & retail | 2019 |
| Day House Farms Limited | Agriculture & fishing | 2012 |
| Day Limited | Wholesale & retail | 2015 |
| Daytona Logistics Limited | Professional & scientific | 2022 |
| Dazesclothing Ltd | Wholesale & retail | 2025 |
| DB22 Speaker Academy Ltd | Education | 2024 |
| DBC Constructions Ltd | Construction | 2023 |
| DBF Property Services Limited | Construction | 2021 |
| Dbosh Limited | Professional & scientific | 2018 |
| DBX Construction Ltd | Construction | 2024 |
| DBX Plant Hire Ltd | Administrative & support | 2024 |
| DBX Property Developments Ltd | Real estate | 2024 |
| DC Associates T/A Basics Ltd | Wholesale & retail | 2022 |
| DC Driver Training Ltd | Education | 2023 |
| DC FFF Coaching LLP | | 2025 |
| DC Ground Services Limited | Administrative & support | 2014 |
| DC Group Services South West Limited | Professional & scientific | 2019 |
| DC Tyres Swindon Limited | Wholesale & retail | 2025 |
| DC11 Limited | Real estate | 2022 |
| DCB Accounting Ltd | Professional & scientific | 2021 |
| DCB Consultoria & Services Ltd | Professional & scientific | 2024 |
| Dcgm Ltd | Administrative & support | 2025 |
| DCK Accounting Solutions Limited | Professional & scientific | 1999 |
| DCK Payroll Solutions Limited | Professional & scientific | 2016 |
| DCK Tech Ltd | Information & communication | 2013 |
| Dcph Ltd | Construction | 2016 |
| Dcsi Properties Limited | Real estate | 2025 |
| Dctit Limited | Wholesale & retail | 2015 |
| DD Maciej Debowski Ltd | Transport & logistics | 2018 |
| DDC Infrastructure Ltd | Other services | 2016 |
| Ddoaba Ltd | Transport & logistics | 2025 |
| Ddrj Support Limited | Health & social care | 2014 |
| DE L'Oum Limited | Wholesale & retail | 2024 |
| DE Melo Brothers Ltd | Arts & recreation | 2025 |
| DE Pass Farms LLP | | 2025 |
| DE Quincy Stone Ltd | Construction | 2018 |
| DE Roberts Heritage Ltd | Real estate | 2026 |
| DE Rosa Consulting Limited | Professional & scientific | 2018 |
| Deacon & SON (Swindon) Limited | Wholesale & retail | 1913 |
| Dead Cool Club. Ltd | Wholesale & retail | 2024 |
| Dead Easy Legal Ltd | Professional & scientific | 2021 |
| Dean Jefferies Construction Limited | Construction | 2003 |
| Deana Baker Jewellery Ltd | Manufacturing | 2026 |
| Deanne Raseta Limited | Professional & scientific | 2021 |
| Deansgate Lane Management Company Limited | Extraterritorial | 2009 |
| Deaves Court Management Limited | Households | 1995 |
| DEB Accountants & Payroll Limited | Professional & scientific | 2025 |
| Debbie Bites Ltd | Manufacturing | 2023 |
| Debyin Property Ltd | Real estate | 2022 |
| Debz Performing Arts Education LLP | | 2021 |
| DEC & Spray Solutions Ltd | Construction | 2023 |
| DEC Kaye Heating and Plumbing Ltd | Construction | 2026 |
| DEC Limited | Transport & logistics | 2015 |
| DEC Window Cleaning Services Ltd | Administrative & support | 2023 |
| Decimal. (UK) Limited | Wholesale & retail | 2005 |
| Decisive Edge Consulting Limited | Professional & scientific | 2011 |
| Deck Base Limited | Manufacturing | 2022 |
| Decoration and Balloon Hire Limited | Hospitality | 2022 |
| Decorative Concrete Specialists Ltd | Construction | 2014 |
| Deda’S Place Ltd | Other services | 2025 |
| Dede Associates Limited | Construction | 2016 |
| Dedecoman Ltd | Transport & logistics | 2025 |
| Dedoti Ltd | Health & social care | 2024 |
| DEE JAY Care Ltd | Health & social care | 2021 |
| Deeksha Technologies Ltd | Information & communication | 2018 |
| Deepa 1 UK Ltd | Households | 2022 |
| Deepa 86 Ltd | Wholesale & retail | 2024 |
| Deepshockdetails Limited | Administrative & support | 2025 |
| Deerfield Services Limited | Real estate | 2021 |
| Defalley Solutions Ltd | Information & communication | 2016 |
| Defash Global Ventures Limited | Wholesale & retail | 2017 |
| Definitive Edge Ltd | Information & communication | 2025 |
| Degeorgia Ltd | Health & social care | 2018 |
| Dektito Ltd | Real estate | 2025 |
| Dekvota Limited | Professional & scientific | 2006 |
| Delacruz Resourcing Solutions Ltd | Professional & scientific | 2022 |
| Delegate VA - Virtual Assistant Limited | Administrative & support | 2019 |
| Delgoa Ltd | Wholesale & retail | 2023 |
| Deliver Events Limited | Information & communication | 2015 |
| Deliver Your Motorcycle Limited | Wholesale & retail | 2025 |
| Delivery Success Ltd | Transport & logistics | 2018 |
| Delkant Ltd | Other services | 2019 |
| Dellers (Swindon) Limited | Wholesale & retail | 1946 |
| Delphi Services Ltd | Information & communication | 2007 |
| Delta Boiler Services Ltd | Construction | 2021 |
| Delta Metrology Limited | Administrative & support | 2011 |
| Delta Telos Consulting Ltd | Information & communication | 2025 |
| Demo Reformer Limited | Arts & recreation | 2025 |
| DEN Contractors Ltd | Construction | 2022 |
| Dencomp Equipment Limited | Wholesale & retail | 2006 |
| Dencomp Holdings Ltd | Financial services | 2021 |
| Dencomp Services Limited | Manufacturing | 2008 |
| Dennis & Turnbull Group Limited | Professional & scientific | 2010 |
| Dennis & Turnbull Limited | Professional & scientific | 2003 |
| Dennis's Removals Limited | Transport & logistics | 1993 |
| Dennis's Vehicle Solutions Limited | Wholesale & retail | 2025 |
| Dented Pride Ltd | Other services | 2005 |