| Deeside Dragons IHC Limited | Chester | 2024 |
| Deeside Fight Club Ltd | Deeside | 2018 |
| Deeside Gliding Club (Aberdeenshire) Limited | Aboyne | 1960 |
| Deeside Gymnastics Club Limited | Wallasey | 2016 |
| Deeside MAC Ltd | Ellesmere Port | 2021 |
| Deeson & Deeson Limited | London | 2013 |
| Deetix Ltd | Leicester | 2022 |
| Deewee Limited | Potters Bar | 2015 |
| Deezi Management Limited | Northampton | 2007 |
| Default Ltd | Bow | 2020 |
| Default Position Ltd | Halesworth | 2012 |
| Defence and Fitness Rooms Limited | Haverhill | 2019 |
| Defence Darts Community Ltd | Marlow | 2026 |
| Defence Photography Limited | Hexham | 2014 |
| Defend | London | 2016 |
| Defender Boxing Ltd | London | 2023 |
| Defiance Music CIC | Penryn | 2025 |
| Defiance Productions Ltd | London | 2022 |
| Defiant Events Ltd | Littlehampton | 2021 |
| Defiant Vibrations Ltd | Nottingham | 2024 |
| Defibfest Limited | Guildford | 2022 |
| Defibrillator Productions Limited | Sittingbourne | 2012 |
| Defier Ltd. | Cardiff | 2013 |
| Define Fitness Falkirk Ltd | Liverpool | 2025 |
| Define Productions Ltd | Abingdon | 2025 |
| Define Your Movement Ltd | Margate | 2026 |
| Defined Strength HQ Limited | Falkirk | 2026 |
| Definition Body Coaching Limited | York | 2017 |
| Definition Dance Ltd | Chelmsford | 2020 |
| Definition Events Limited | London | 2008 |
| Definition Gym Crawley Limited | Hadlow | 2026 |
| Definition Gym Tonbridge Limited | Hadlow | 2022 |
| Definition Music Limited | Barnet | 2009 |
| Definitions Fitness Ltd | Birmingham | 2022 |
| Definitive Entertainment Ltd | Abingdon | 2023 |
| Definitive Productions Limited | London | 2004 |
| Definitive Space Limited | London | 2010 |
| Definitive Special Projects Limited | Stevenage | 1992 |
| Defo Group Limited | Sittingbourne | 2019 |
| Defoe Enterprises Limited | Birmingham | 2002 |
| Defragmental Productions Ltd | Woking | 2022 |
| Defreitas Limited | Biggleswade | 2018 |
| Defrosted Limited | London | 2023 |
| Defunked Entertainment Limited | Manchester | 2022 |
| Defy Gravity Ltd | Tunstall | 2012 |
| Defy Limitation Fitness Ltd | North Ferriby | 2021 |
| Defy Limitations Ltd | Brierley Hill | 2017 |
| Defying Gravity Academy CIC | Newport | 2019 |
| Defytheoddscoaching Ltd | Elgin | 2024 |
| Deganwy Productions Limited | Cheadle | 2025 |
| Degenerate FOX Theatre Ltd | London | 2020 |
| Deggi & YEO Ltd | London | 2013 |
| Degreeart Asia Ltd | Thames Ditton | 2007 |
| Degrees of Error Ltd | Bristol | 2025 |
| Deiago Ltd | Manchester | 2018 |
| Deighton Into Sport Project | Huddersfield | 2010 |
| Deinonychus Ltd | Barnet | 2009 |
| Deir Martin Ltd | Banbury | 2022 |
| Deirdre Angella Limited | Bristol | 2018 |
| Deity Dance Limited | London | 2023 |
| Deja VU Productions Limited | Nottinghamshire | 2005 |
| Deja-Vuh Limited | London | 2015 |
| Dejahdesigns Limited | London | 2022 |
| Dejoni Arts Ltd | London | 2020 |
| Dekaur Ltd | Leicester | 2023 |
| Dekdolly Ltd | Bath | 1991 |
| Dekkle Printmaking Studios Limited | Arlesey | 2008 |
| Dekoda Arts Ltd | Weymouth | 2024 |
| Dekoning Leisure Group Ltd | Bolton | 2000 |
| Dektora Ltd | London | 2020 |
| DEL BOY International Limited | Edinburgh | 1995 |
| DEL Buono Limited | Sunderland | 2010 |
| DEL Gentleman Limited | Hertfordshire | 2003 |
| DEL Porto Ltd | Doncaster | 2017 |
| DEL Promotions Ltd | Newry | 2025 |
| Del's Fitness Centre Ltd | Gravesend | 2008 |
| Delaink Tattoo Ltd | London | 2024 |
| Delamere Forest Golf Club Limited | Nr Northwich | 1910 |
| Delamere Outdoor Fitness Ltd | Wrexham | 2013 |
| Delamore Arts Ltd | Plymouth | 2004 |
| Delaney & SON Ltd | Brighton | 2012 |
| Delaney Gold Limited | London | 2011 |
| Delaney Grey Ltd | Newbury | 2023 |
| Delapre Abbey Preservation Trust | Northampton | 2006 |
| Delapre Golf Centre Limited | Northampton | 2003 |
| Delaross Ltd | Halifax | 2016 |
| Delboys Entertainments Ltd | Bristol | 2003 |
| Dele Alli Promotions Ltd | London | 2014 |
| Delegate Investments Limited | Hexham | 2019 |
| Delegated Production Limited | London | 2018 |
| Delete Brands Ltd | London | 2025 |
| Delete Ventures Ltd | Tonbridge | 2023 |
| Delfont Mackintosh Theatres Limited | London | 1990 |
| Delgado Sport Ltd | London | 2024 |
| Delgado Tennis Bookings Limited | Bristol | 2026 |
| Deli Experiences Ltd | London | 2018 |
| Delich Co Limited | London | 2021 |
| Delicious Racing Ltd | Norwich | 2023 |
| Delidong Limited | Braintree | 2022 |
| Delight Coaching Ltd | Aldershot | 2026 |