| Diamond Libra Property Limited | Northampton | 2018 |
| Diamond Logistics Guildford Limited | Guildford | 2021 |
| Diamond Music Limited | Lincoln | 1996 |
| Diamond Paintings Limited | Eastleigh | 2014 |
| Diamond Payroll Services Ltd | Tamworth | 2009 |
| Diamond Pest Control Limited | Hoddesdon | 2015 |
| Diamond Reality Limited | Nottingham | 2001 |
| Diamond Road 1959 Limited | Launceston | 2014 |
| Diamond Security Centres Limited | London | 1988 |
| Diamond Shelf Number 27 Limited | Magherafelt | 2013 |
| Diamond Shelf Number 34 Limited | Magherafelt | 2014 |
| Diamond Sports Events Limited | Christchurch | 2007 |
| Diamond West Limited | Maidstone | 2017 |
| Diamond Wolf Designs Ltd | Exeter | 2020 |
| Diamonds 4 Staff Limited | Hemsworth, Pontefract | 2015 |
| Diamonds Factory Ltd | Pinner | 2013 |
| Diamonds for Humanity Limited | London | 2004 |
| Diamonds UN Limited | Swansea | 2022 |
| Dian LUO Ltd | London | 2013 |
| Diana Buraka Ltd | Bristol | 2015 |
| Diana Control Invest Limited | London | 2025 |
| Diana Control Limited | London | 2025 |
| Diana Edens Tradgard Investment Limited | London | 2021 |
| Diana Edens Tradgard Limited | London | 2021 |
| Diana Ellis Jones Ltd | Bristol | 2015 |
| Diana Gallego Limited | Bridgwater | 2014 |
| Diana Korobovaite Ltd | Kettering | 2022 |
| Diana Kraujuniene Limited | Kettering | 2022 |
| Diana Kvedariene Ltd | Dungannon | 2023 |
| Diana Mary Treanor Ltd | Birmingham | 2024 |
| Dianne Marshall Limited | Liverpool | 2009 |
| Dias & Co Norway Limited | London | 2023 |
| Diasam Ltd | Leicester | 2021 |
| Diba Limited | Bideford | 2002 |
| Diblue Ltd | London | 2007 |
| Dicallen New Control Tech of Doors and Windows London Co., Ltd | Cardiff | 2019 |
| Dichun Clothing Co., Ltd | Kington | 2021 |
| Dick O' the Banks Limited | Dorchester. | 1962 |
| Dick's Tea Bar Limited | London | 1997 |
| Dickens Limited | Eastleigh | 1983 |
| Dickenstar Limited | Swansea | 2001 |
| Dickiebird Film Ltd | London | 2022 |
| Dickinson & Morris Limited | Leicester. | 1938 |
| Dickinson Dees Limited | London | 2007 |
| Dickinson Farm Services Ltd | Sheffield | 2025 |
| Dickshaunharry Ltd | Kington | 2021 |
| Dickson, Middleton & Co. Limited | | 1997 |
| Dicky G Studio Limited | Rayleigh | 2012 |
| Diclass Equine Ltd | Stevenage | 2020 |
| Didactica Ltd | Leicester | 2015 |
| Didata Limited | Bilston | 1996 |
| Diddly Squat Limited | Barnet, | 2009 |
| Diddy Dribblers Ltd | Rossendale | 2016 |
| Didomi Ltd | Knaresborough | 2024 |
| DIE Starke Organisation Ltd | London | 2023 |
| DIE Technology Limited | Norwich | 1983 |
| Diecast Legends Limited | Guildford | 2013 |
| Dieci Ltd | Newry | 2010 |
| Dieci UK Ltd | Newry | 2010 |
| Diego Building Services Ltd | Ilford | 2024 |
| Diego Media Ltd | Manchester | 2020 |
| Diem Botanics UK Ltd | London | 2019 |
| Diemme Global Limited | London | 2019 |
| Diepat Limited | Northamptonshire | 1966 |
| Diesel Bros Ltd | Carterton | 2023 |
| Diesel DYE Limited | Newcastle | 2008 |
| Diesel Industries Limited | Preston | 2016 |
| Diesel Injection (UK) Limited | Coventry | 2015 |
| Diesel Works Limited | Torquay | 2010 |
| Dieselink Services Limited | Larbert | 1989 |
| Dieterle Europe Chemical Co., Ltd. | London | 2023 |
| Dietrich Vermoegensverwaltung Ltd | London | 2023 |
| Diez UK Limited | Leicester | 2011 |
| Difaiq Invest Limited | London | 2023 |
| Difaiq Limited | London | 2023 |
| Different Holdings Ltd | Norwich | 2022 |
| Different Shelf Limited | Reading | 2011 |
| Difficult Name Limited | Bexley | 2023 |
| Diffusione Culturale Limited | Peterborough | 2023 |
| Diffx Limited | Huddersfield | 2010 |
| Difly Technology Ltd | Bromley | 2026 |
| Difuria Plant Hire Ltd | Doncaster | 2010 |
| DIG Deep Communications Ltd | Hove | 2020 |
| DIG Less Ltd | Redditch | 2023 |
| Digby Brothers Ltd | Colchester | 2004 |
| Digby Stone Limited | Colchester | 2013 |
| Digdug Limited | Southend-On-Sea | 2022 |
| Diggens Limited | Beckenham | 2013 |
| Digger & Forklift Parts UK Limited | Colchester | 2021 |
| Digger School Ltd | Chippenham | 2023 |
| Digger Spares Limited | Colchester | 2021 |
| Diggerland Limited | Rochester | 2009 |
| Diggers and Dreamers Ltd | Great Missenden | 2025 |
| Diggers Direct Limited | Rochester | 2005 |
| Diggerworld Limited | Gravesend | 2002 |
| Digi Temps Services Limited | Worcester | 2022 |
| Digialitay Ltd | Bristol | 2021 |
| Digiarty Ltd | Cambridge | 2016 |
| Digica (FMS) Limited | Hatfield | 1989 |
| Digica Group Holdings Limited | Hatfield | 2002 |