| Adorx Therapeutics Limited | Edinburgh | 2017 |
| Ados Consultancy Limited | London | 2019 |
| Ados Consulting Limited | London | 2026 |
| Ados Professionals Ltd | Nottingham | 2023 |
| Adosa Limited | Warrington | 2017 |
| Adot Healthcare Limited | Coventry | 2023 |
| Adot Services Limited | Harlow | 2020 |
| Adotar AI Limited | Sheffield | 2025 |
| Adotc Design Limited | Canterbury | 2019 |
| Adottimo Limited | London | 2016 |
| Adova Bedding Limited | Rochester | 2018 |
| Adova Mobili Ltd | London | 2019 |
| Adovation Ltd | Leigh | 2008 |
| Adox Ltd | Burnham | 2026 |
| Adox Research Limited | Nottingham | 2018 |
| Adoxa Ecology Ltd | Brentford | 2025 |
| ADP Accountancy Limited | Caterham | 2015 |
| ADP Accounting Limited | Dereham | 2008 |
| ADP Accounting Services UK Limited | Loughton | 2022 |
| ADP Arch Ltd | London | 2017 |
| ADP Architects Limited | Southampton | 2002 |
| ADP Architecture (North) Ltd | London | 2014 |
| ADP Architecture and Design Ltd | Holmfirth | 2016 |
| ADP Architecture Limited | London | 2016 |
| ADP Business Solutions Ltd | Doncaster | 2014 |
| ADP Consulting & Engineering Ltd | Brentwood | 2023 |
| ADP Consulting Limited | Taunton | 2023 |
| ADP Diamex Limited | Dartford | 2004 |
| ADP Engineering Services Ltd | Worthing | 2018 |
| ADP EOT Limited | London | 2016 |
| ADP Executive Consultancy Limited | London | 2017 |
| ADP Finance and Advisory Services Limited | Bristol | 2020 |
| ADP Gestion Ltd | London | 2026 |
| ADP Interior Design Limited | London | 2006 |
| ADP Landscape Architects Ltd | Worcester | 2020 |
| ADP Precision Holdings Limited | Newcastle Upon Tyne | 2010 |
| ADP Reporting and Consultancy Limited | London | 2023 |
| ADP Studio Ltd | Banbury | 2025 |
| Adpad Group Limited | Newton Abbot | 2013 |
| Adparatio Muneris Limited | Shepperton | 2015 |
| Adpconsultancyuk Ltd | London | 2015 |
| Adpearl Enterprises Ltd | Bristol | 2024 |
| Adperform Limited | Hereford | 2014 |
| Adpgiant Limited | Alcester | 2004 |
| Adpl (UK) Ltd | Palmers Green | 2022 |
| Adplan Creative Limited | Maidstone | 2018 |
| Adplusmedia Ltd | Mildenhall | 2026 |
| Adpm Professional Services Ltd | Cleckheaton | 2018 |
| Adpni Ltd | Holywood | 2025 |
| Adport Limited | Bolton | 2018 |
| Adpost Media Limited | South Humberside | 2003 |
| Adpr Limited | Long Sutton | 1999 |
| Adprime Ltd | London | 2023 |
| Adpro Digital Limited | London | 2023 |
| Adpro Solutions Ltd | Aylesbury | 2025 |
| Adprom Limited | Ely | 2004 |
| Adpulse Group Ltd | London | 2025 |
| Adpulsum Consulting Ltd | Wendover | 2017 |
| ADQ Commercial Ltd | Bradford | 2024 |
| ADQ Media Ltd | Ashtead | 2020 |
| Adqa Medical Devices Limited | Blackpool | 2020 |
| Adqc Limited | Leamington Spa | 2023 |
| Adqua Ltd | Isleworth | 2019 |
| ADR and Training Ltd | London | 2025 |
| ADR Architecture Ltd | Birmingham | 2020 |
| ADR Audit Services Limited | Romford | 2016 |
| ADR Consultancy Ltd | Newcastle Upon Tyne | 2011 |
| ADR Consultants Ltd | Manchester | 2017 |
| ADR Consulting Engineers (Essex) Ltd | Herne Bay | 2024 |
| ADR Consulting Engineers (Suffolk) Ltd | London | 2026 |
| ADR Consulting Engineers Ltd | Herne Bay | 2020 |
| ADR Consulting Ltd | Carrickfergus | 2024 |
| ADR COV Limited | Stratford-Upon-Avon | 2007 |
| ADR Delivery Management Limited | London | 2014 |
| ADR Electrical Services Ltd | Darlington | 2020 |
| ADR Engagement Services Ltd | Saltcoats | 2017 |
| ADR Engineering Northwest Ltd | Bolton | 2024 |
| ADR Financial Solutions Limited | London | 2017 |
| ADR Group Holdings Ltd. | London | 2026 |
| ADR Healthcare Consultants Ltd | Blackpool | 2025 |
| ADR Holdings Limited | Morecambe | 2026 |
| ADR Hospitality Group Limited | Edinburgh | 2018 |
| ADR Innovations Limited | Newport Pagnell | 2022 |
| ADR International Limited | Henley-On-Thames | 1986 |
| ADR Legal Resolution Ltd | Sheffield | 2017 |
| ADR Management Services Limited | Derby | 2020 |
| ADR Partnership Limited | Barnstaple | 2023 |
| ADR Professional Services Limited | Belfast | 2016 |
| ADR Sheq Consultancy Ltd | Doncaster | 2014 |
| ADR Solutions (UK) Limited | Woodford Green | 2013 |
| ADR Surveying Limited | Driffield | 2010 |
| ADR Sustainability Ltd | High Wycombe | 2011 |
| ADR Swarn Limited | Coventry | 2020 |
| ADR Watches Limited | Warrington | 2015 |
| Adr-Odr International Limited | London | 2016 |
| ADR100 Ltd | Aylesbury | 2026 |
| Adra Business Services Limited | Stockport | 2018 |
| Adra Domek Limited | Stockport | 2021 |
| Adra Projects Ltd | Bishop Auckland | 2023 |
| Adrachma (UK) Limited | Droylsden | 2023 |