| Dark Stage Ltd | London | 2026 |
| Dark Tower Ltd | London | 2013 |
| Dark Ventures Limited | Herne Bay | 2014 |
| Dark Wood Productions Limited | London | 2015 |
| Dark Yellow DOT C.I.C. | London | 2018 |
| Darkaus Ltd | Wirral | 2008 |
| Darkbeat Entertainment Ltd | London | 2025 |
| Darkchild Productions Ltd | Aylesbury | 2014 |
| Darkcloth Productions Ltd | Tenby | 2016 |
| Darkest Hour Events Ltd. | Bristol | 2015 |
| Darkfield Events Ltd. | London | 2017 |
| Darkhorse ENT Limited | Holborn | 2018 |
| Darkhorse Records Limited | | 1974 |
| Darkjewel Ltd | Wrexham | 2021 |
| Darklight Entertainment Limited | Conwy | 2019 |
| Darkling Productions Limited | Bromsgrove | 2020 |
| Darkmaster Ltd | Crowborough | 2018 |
| Darkmoor Limited | London | 2012 |
| Darkness | London | 2013 |
| Darko and Mash Limited | Leicester | 2021 |
| Darkone Ltd | Plymouth | 2021 |
| Darkperformance Gym Ltd | Callington | 2015 |
| Darkroom Digital Limited | Bath | 2006 |
| Darkside Floyd Show Limited | Wolverhampton | 2015 |
| Darkside Rising C.I.C. | Lincoln | 2020 |
| Darkstar Corporation Limited | Slough | 2009 |
| Darkstar Laser Limited | Dudley | 2008 |
| Darlaston Town (1874) Football Club C.I.C. | Walsall | 2013 |
| Darlaston Town FC Limited | West Midlands | 2023 |
| Darley Moor Motor Cycle Road Racing Club Limited | Ashbourne | 1980 |
| Darley Moor Paramotoring Limited | Buxton | 2017 |
| Darlin Yachting Ltd | London | 2023 |
| Darling Byrne Ltd | London | 2016 |
| Darling GEM Designs Ltd | Stevenage | 2024 |
| Darling Group UK Ltd | Ferndown | 2024 |
| Darlington & District Motor Club Limited | Newcastle Upon Tyne | 1956 |
| Darlington 1883 Limited | Darlington | 2012 |
| Darlington 24/7 Limited | Darlington | 2016 |
| Darlington Arena Limited | Darlington | 2011 |
| Darlington Community Carnival | Darlington | 2012 |
| Darlington Cricket and Athletic Club C.I.C. | Darlington | 2016 |
| Darlington Delaire Creative Ltd | Romford | 2025 |
| Darlington Dog Show Society Limited | Seaham | 2012 |
| Darlington Golf Club (Members) Limited(The) | Co Durham. | 1976 |
| Darlington Gymnastics Club | Darlington | 2013 |
| Darlington Harriers & Athletics Club | Darlington | 2021 |
| Darlington Indoor Bowls Club Limited | Darlington | 2008 |
| Darlington Mowden Park Rugby Football Club Limited | Darlington | 2005 |
| Darlington Rugby Football Club Limited | County Durham | 1996 |
| Darlton Gliding Club Ltd | Newark | 2007 |
| Darnall FA Limited | Sheffield | 2015 |
| Darne PT Limited | Woodford Green | 2026 |
| Darq Studios Limited | Windsor | 2015 |
| Darra Entertainment Ltd | London | 2022 |
| Darrell Warner Ltd | Cirencester | 2003 |
| Darren & Lilia Dance Studio Limited | Farnham | 2023 |
| Darren Agnew Design Animation Limited | | 2005 |
| Darren Bell Productions Limited | London | 2025 |
| Darren Bell Services Ltd | London | 2025 |
| Darren Bishop Tattoos Limited | Glasgow | 2023 |
| Darren Evans Touring Ltd | Dudley | 2026 |
| Darren Fletcher Promotions Limited | Sale | 2004 |
| Darren Hayman Ltd | Doncaster | 2003 |
| Darren Hogg Music Ltd | Quinton | 2012 |
| Darren J. Benjamin Music Ltd | Basingstoke | 2015 |
| Darren Lewis-Harris Ltd. | Walthamstow | 2011 |
| Darren MMA Limited | Edgware | 2020 |
| Darren Reeves Productions Ltd | Petersfield | 2019 |
| Darren Reid Paintings Limited | Derby | 2017 |
| Darren Reynolds Limited | Ascot | 2017 |
| Darren Turner Golf Academy Ltd | Benfleet | 2014 |
| Darren Wilson Personal Training Ltd | Harrow | 2018 |
| Darren Wilson PT Ltd | Pontypridd | 2020 |
| Darren Woodhead Limited | Peebles | 2015 |
| Darrens Dazzling Entertainment Limited | London | 2025 |
| Darrington Equestrian Centre Limited | Pontefract | 2013 |
| Darrington Golf Club Limited | Thorne | 2005 |
| Darryl J Walsh Limited | Burnham-On-Sea | 2026 |
| Darryl Studios Ltd | Plymouth | 2025 |
| Darryl's Lilypad Ltd | Crawley | 2015 |
| Dart Amusements Limited | Swansea | 2014 |
| Dart Dash Ltd | Blackpool | 2025 |
| Dart Health Limited | Paignton | 2021 |
| Dart Music Festival Limited | Dartmouth | 2008 |
| Dart Polo Academy Ltd | Gainsborough | 2024 |
| Dart Polo Club Ltd | Gainsborough | 2024 |
| Dart Scene Ltd | Kirkby In Ashfield | 2025 |
| Dart Soft Ltd | St. Leonards | 2017 |
| Dart Zone Ltd | Darwen | 2017 |
| Darta AI Ltd | Altrincham | 2024 |
| Dartasylum Competitions Ltd | Bristol | 2025 |
| Dartasylum Group Ltd | Bristol | 2024 |
| Dartdale Limited | South Yorkshire | 1992 |
| Dartford District Schools FA Limited | Rochester | 2016 |
| Dartford Engraving & Screenprinting Limited | Slade Green Road | 1976 |
| Dartford F.C. (1992) Limited | Dartford | 1992 |
| Dartford Football Club Youth Development Centre C.I.C. | Dartford | 2012 |
| Dartford Golf Club Limited | Dartford | 1930 |
| Dartford Health and Sports Club | Dartford | 2022 |
| Dartford Rugby Limited | Dartford | 2014 |