| Admiral Vending Systems Limited | Swansea | 2017 |
| Admiralcollections Cares Limited | London | 2018 |
| Admiralis Limited | London | 2009 |
| Admiralty Arch (UK) Limited | London | 2018 |
| Admiralty Street Ltd | Plymouth | 2017 |
| Admire Cleaning Ltd | London | 2025 |
| Admire Consulting Ltd | Manchester | 2015 |
| Admire Digital Limited | Prestwick | 2013 |
| Admire HR Services Ltd | Watford | 2018 |
| Admire Landscapes Ltd | Faversham | 2022 |
| Admissia Associates Limited | Deeside | 2013 |
| Admistaff Limited | Guildford | 2025 |
| Admitrade Ltd | London | 2018 |
| Adml Limited | Chelmsford | 1999 |
| Admn Consultancy Ltd | London | 2024 |
| Admonds Services Limited | London | 2015 |
| Admore People Limited | Surbiton | 2023 |
| Admore Recruitment Limited | Leeds | 2009 |
| Admr Property Services Ltd | Basingstoke | 2023 |
| Admt Business Solutions Limited | Orpington | 2021 |
| Admynex Limited | Ossett | 2024 |
| ADN Recruitment Ltd | London | 2025 |
| Adnah Healthcare Limited | Chelmsford | 2018 |
| Adnama Consultancy Services Ltd | Datchet | 2017 |
| Adnan Car Hire Ltd | Reading | 2023 |
| Adnanhayat Ltd | Woodford Green | 2023 |
| Adnd Limited | London | 2018 |
| Adnin Outsourcing UK Limited | Harlow, Essex, | 2023 |
| Adnix UK Limited | Chorley | 2008 |
| Adnod CYF | Cardiff | 2010 |
| ADO Eiendom 80 Ltd | Stockport | 2011 |
| ADO PAY Ltd | Halifax | 2022 |
| Adobe Services Limited | Aylesbury | 2016 |
| Adobe Systems Europe Limited | Edinburgh | 1986 |
| Adobix Ltd | Enfield | 2023 |
| Adoddle Ltd | Newent | 2021 |
| Adolfo Harrison Gardens Limited | London | 2016 |
| Adolfsen Elektro Ltd | Pencoed, Bridgend | 2016 |
| Adolph Numerical Controls Limited | Herts | 1975 |
| Adolphus Group Limited | London | 2006 |
| Adomako Basoah Secretaries Limited | South Croydon | 2003 |
| Adomba Solutions Limited | Dunstable | 2024 |
| Adon Cleaning Ltd | Coventry | 2025 |
| Adonai Care Services Ltd | Bournemouth | 2017 |
| Adonai Caring Limited | Barnet | 2014 |
| Adonai Services Limited | Chatham | 2017 |
| Adonai Travel Limited | London | 2013 |
| Adonis (UK) Limited | Leeds | 2012 |
| Adonyah Friends Ltd | London | 2022 |
| Adopt a Rescue Dobermann UK Ltd | Congleton | 2025 |
| Adopt Labs Limited | Wickford | 2024 |
| Adopt-A-Child | Inverness | 1999 |
| Adoptsmt UK Ltd. | Bicester | 2008 |
| Ador Resourcing Ltd | Barking | 2018 |
| Ador Solutions Ltd | Bolton | 2025 |
| Ador Talent Limited | London | 2022 |
| Adora Global Limited | Stoke-On-Trent | 2025 |
| Adora Ventures Care Limited | London | 2016 |
| Adorable Dogs Ltd | Chippenham | 2006 |
| Adorable Sloth Ltd | London | 2016 |
| Adore 2 Care Ltd | Windsor | 2019 |
| Adore Holidays Limited | Stanstead Abbotts | 2011 |
| Adore Landscapes Limited | Alton | 2024 |
| Adore Recruitment Ltd | London | 2013 |
| Adored by Ellingworths Ltd | Blackpool | 2012 |
| Adored Sports & Entertainment Ltd | Ipswich | 2017 |
| Adorn Packaging Ltd | Leicester | 2024 |
| Adornare Ltd | Bedford | 2026 |
| Adorne Window Cleaning Limited | Harrow | 2025 |
| Adot LED UK Limited | Sidcup | 2018 |
| Adox Travel Limited | Nottingham | 2019 |
| Adoyx-Uk Limited | Warrington | 2025 |
| ADP Action Limited | Basildon | 2022 |
| ADP Call Centres Ltd | Manchester | 2000 |
| ADP Chessington Pensions Trustees Limited | Staines-Upon-Thames | 1999 |
| ADP Chiropractic Limited | Walsall | 2021 |
| ADP Cleaning Services Ltd | Llanelli | 2023 |
| ADP Consultants Ltd | London | 2023 |
| ADP Europe Ltd | Cardiff | 2012 |
| ADP Fire and Security Limited | St. Neots | 2015 |
| ADP Homecare Property Maintenance Ltd | Peterborough | 2025 |
| ADP Precision Engineering Limited | Newcastle Upon Tyne | 2002 |
| ADP Primary Care Acquisitions Limited | Leeds | 2009 |
| ADP Security Systems Limited | Liphook | 1996 |
| Adpak Limited | Chessington | 2025 |
| Adpax Management Company Limited | Magherafelt | 1999 |
| Adpeventworld Ltd | London | 2018 |
| Adptc Ltd | West Byfleet | 2014 |
| ADR Concepts Ltd | London | 2023 |
| ADR Facilities Management Ltd | Telford | 2013 |
| ADR Global Services Limited | Southampton | 2023 |
| ADR Ground Care Ltd | Stoke-On-Trent | 2024 |
| ADR Landscapes Limited | Alnwick | 2017 |
| ADR Mechanical Installations Limited | Gornall Wood | 2015 |
| ADR Mortgage Finance Ltd | Ware | 2017 |
| ADR Mortgage Services Limited | Bolton | 2022 |
| ADR Plant Hire and Repair Limited | Solihull | 2026 |
| ADR Services & Solutions Limited | Preston | 2015 |
| ADR Specialists Ltd | Liverpool | 2021 |
| ADR Ventures Limited | Cambridge | 2026 |