| Decent Music Ltd | London | 2025 |
| Decentric Music Ltd. | Teddington | 1986 |
| Deception Escape Rooms Ltd | Matlock | 2017 |
| Deceptive Music Limited | Doncaster | 1993 |
| Deceptive Records Limited | Doncaster | 1993 |
| Decibel Songs Music Publishing (UK) Limited | Borehamwood | 2015 |
| Decibel Sport Management Limited | Stockport | 2022 |
| Decisive Digital Ltd | London | 2011 |
| Decisive Management Limited | Stevenage | 2012 |
| Deck Events Limited | Manningtree | 2020 |
| Deck Heads Ltd | Basildon | 2021 |
| Deckdale Limited | Shaftesbury | 2018 |
| Decked OUT Competitions Ltd | Ashford | 2025 |
| Decked OUT Limited | London | 2000 |
| Deckinate Ltd | Northwich | 2023 |
| Decks Factor Ltd. | Hemel Hempstead | 2016 |
| Declan Carroll Racing Limited | Malton | 2003 |
| Declan LEE Motorsports Limited | Horsham | 2021 |
| Deco Digital Limited | Birmingham | 2014 |
| Deco Productions Limited | London | 2003 |
| Decoder Art CIC | St. Ives | 2020 |
| Decolonise C.I.C. | London | 2019 |
| Decomyn Art Limited | Droitwich | 2026 |
| Deconstruction Limited | London | 1994 |
| Deconstructivity Limited | London | 2020 |
| Decopica Ltd | Harpenden | 2021 |
| Decor NO 5 Limited | London | 2018 |
| Decor Sisters Ltd | Castleford | 2025 |
| DECOR8 INT Ltd | Cardiff | 2019 |
| Decorative Arts DMI Limited | London | 2014 |
| Decordia Limited | Manchester | 2016 |
| Decosa Limited | London | 2012 |
| Decosta Music Ltd | Stevenage | 2019 |
| Decote Dance Ltd | Whitley Bay | 2014 |
| Decoupage Ltd | London | 2020 |
| Decoy LEG Ltd | Glasgow | 2025 |
| Deddington Rocks Festival CIC | Banbury | 2025 |
| Dedham Angling Club Ltd | Colchester | 2024 |
| Dedicate Health and Fitness Ltd | Coventry | 2012 |
| Dedicated by Doyle Ltd | Newry | 2021 |
| Dedicated Conditioning Scotland Limited | Stirling | 2024 |
| Dedicated Digital Limited | Cardiff | 2025 |
| Dedicated Fitness Gym Limited | Newry | 2017 |
| Dedicated Fitness Limited | Alton | 2025 |
| Dedicated Limited | London | 1989 |
| Dedicated OPS Ltd | Liverpool | 2026 |
| Dedicated Physiques Ltd | Bognor Regis | 2025 |
| Dedicated R&R Ltd | Alton | 2026 |
| Dedicated Supergym Ltd | Liverpool | 2019 |
| DEE Caffari Ltd | Fareham | 2006 |
| DEE Capital Limited | St. Helens | 2025 |
| DEE MAI Ltd | London | 2023 |
| DEE Sheehan Limited | Lewes | 2002 |
| DEE Theatre Arts Ltd | Ampney Crucis | 2013 |
| DEE Trading Limited | Blackpool | 2023 |
| DEE Valley Martial Arts, Fitness and Performance Ltd | Llangollen | 2024 |
| Deeds Network Ltd | London | 2026 |
| Deehampton Productions Ltd | Birchington | 2023 |
| Deejay Whales Limited | Rowley Regis | 2024 |
| Deejays Locker Limited | Southampton | 2016 |
| Deekshaa CIC | Bromsgrove | 2020 |
| Deelights Photography Limited | Bedworth | 2013 |
| Deelo Arizona Ltd | London | 2025 |
| Deemed Fresh Entertainment Limited | Hayes | 2017 |
| Deemouth Artist Studios Limited | Aberdeen | 2019 |
| Deemouth Workshops Ltd | Aberdeen | 2023 |
| Deep Arts Ltd | Hamilton | 2019 |
| Deep Blue C Limited | South Croydon | 2007 |
| Deep Blue Productions Limited | London | 1997 |
| Deep Body Health Ltd | Milton Keynes | 2016 |
| Deep Canyon Ltd | London | 2025 |
| Deep Cover Limited | Oxford | 2016 |
| Deep Dish Beach Academy Ltd | Olney | 2019 |
| Deep Dish Beach Home Ltd | Olney | 2021 |
| Deep Dish Beach Ltd | Olney | 2017 |
| Deep END Management Ltd | Shepherds Bush | 2020 |
| Deep END Records Limited | Oxford | 2018 |
| Deep Fried Scenery Limited | Redhill | 2019 |
| Deep Green Limited | Sheffield | 2021 |
| Deep Harmony Limited | London | 1994 |
| Deep Nature Ltd | London | 2015 |
| Deep Presents Ltd | Blackburn | 2022 |
| Deep Studios Ltd | London | 2016 |
| Deep Tattoo Studio Ltd | Southall | 2026 |
| Deep-Management Ltd | London | 2025 |
| Deep-Sea Leisure PLC | | 1991 |
| Deepcoremarine Ltd | Ruislip, | 2022 |
| Deeper Spaces Ltd | London | 2021 |
| Deeping Rangers Football Club Ltd | Peterborough | 2020 |
| Deeping Sports & Social Club | Market Deeping, Peterborough | 1999 |
| Deepings Rugby Union Football Club Limited | Deeping St James | 2017 |
| Deepjam Limited | York | 2007 |
| Deeply Armed Limited | Belfast | 2015 |
| Deepmatter Records Limited | London | 2019 |
| Deepsheep Limited | Battle | 2024 |
| Deepstream Ltd | Greenock | 2012 |
| Deer Shed Festival Ltd | Southwark | 2010 |
| Deerness Gymnastics Academy Ltd | Durham | 2011 |
| Deeside Agricultural Association | Aberdeen | 2003 |
| Deeside Bookmakers Ltd. | Edinburgh | 2003 |