| Addoceo Consultancy Limited | Macclesfield | 2014 |
| Addoil Limited | South Ruislip | 2012 |
| Addoli Ltd | Blaenavon | 2025 |
| Addon Solutions Limited | Great Brickhill | 2016 |
| Addonova Limited | Rickmansworth | 2014 |
| Addooco Ltd | London | 2025 |
| Addos Consulting Limited | Southampton | 2003 |
| Addp Limited | Cheltenham | 2024 |
| Addqual Ltd | Derby | 2015 |
| Addquest Limited | Billingham | 1989 |
| Addr Portfolio Services Limited | Manchester | 2023 |
| Address Limited | Horsham | 2014 |
| Address Robotics Limited | London | 2023 |
| Addressed Limited | Cardiff | 2021 |
| Addresshq Ltd | London | 2026 |
| Addressing Domestic Abuse Community Interest Company | Durham | 2021 |
| Adds Business Solutions Limited | Motherwell | 2016 |
| Adds Resourcing Limited | Caldicot | 2016 |
| Adds Sparkle Limited | Norwich | 1994 |
| Addsale Ltd | London | 2013 |
| Addsc Limited | Woking | 2025 |
| Addsubtract Ltd | London | 2025 |
| Addsum Consultants Limited | Wembley | 2016 |
| Addsum Limited | Southampton | 2015 |
| Addtract Limited | Salford | 2025 |
| Adduco Capital Partners Limited | Cambridge, | 2013 |
| Adduco Ltd | York | 2012 |
| Addumara Ltd | London | 2016 |
| Addup Bookkeeping Ltd | Ilkeston | 2016 |
| Addvantage Ledgers Ltd | Aberdeen | 2025 |
| Addvantage Marketing Limited | Marlow | 2013 |
| Addvantage UK Ltd | London | 2014 |
| Addveritas Ltd | London | 2011 |
| Addvert Ltd | Bedford | 2018 |
| Addvisory Limited | Chelmsford | 2017 |
| Addw Ltd | Greater London | 2026 |
| Addwell Scotland Ltd | Dunblane | 2023 |
| Addwills Limited | South Croydon | 2009 |
| Addwings Expand International Ltd | Dartford | 2025 |
| Addwings Travel & Image Limited | Orpington | 2025 |
| Addworx Limited | Stockport | 2022 |
| Addy Murgatroyd Accountants Ltd | West Yorkshire | 2008 |
| Addy Murgatroyd Ltd | Holmfirth | 2019 |
| Addy Murgatroyd Services Ltd | Holmfirth | 2008 |
| Addy Products Limited | Botley | 1947 |
| Addy-Kassova Audience Strategy Limited | Kingston Upon Thames | 2012 |
| Addycar Ltd | London | 2017 |
| Addyce Consulting Limited | Welling | 2007 |
| Addyson Monitoring Services Limited | Tewkesbury | 2010 |
| Addyson Pope Limited | Leeds | 2024 |
| Addytec Limited | Harrogate | 2016 |
| ADE (Edinburgh) Limited | Edinburgh | 2020 |
| ADE Accounting Limited | Coventry | 2016 |
| ADE Adesina & Co Limited | Sheffield | 2013 |
| ADE Ajibulu Consulting Limited | London | 2011 |
| ADE Architecture Limited | London | 2008 |
| ADE Awoye ARC Ltd | London | 2020 |
| ADE Commercial Ltd | London | 2026 |
| ADE Consult Ltd | Telford | 2020 |
| ADE Consulting Services Ltd | Paisley | 2024 |
| ADE Engineering Limited | Warwick | 2024 |
| ADE Holdings Limited | London | 2018 |
| ADE Hopkins Limited | Hitchin | 2017 |
| ADE Industrial Limited | Kington | 2019 |
| ADE Investments Ltd | Mexborough | 2024 |
| ADE Nexus Limited | Leeds | 2026 |
| ADE Parent Limited | Morecambe | 2019 |
| ADE Press Ltd | Harrow | 1996 |
| ADE Tax Limited | London | 2018 |
| ADE Transition Consulting Ltd | Fleet | 2021 |
| Ade-K Ventures Ltd | Luton | 2019 |
| Ade-Law Consultancy Limited | Thornton Heath | 2022 |
| Adea Concepts Limited | Glasgow | 2025 |
| Adea Consultancy Ltd | London | 2024 |
| Adealon (Group Legal Services) Limited | Preston | 2000 |
| Adealon (UK) Limited | Preston | 1998 |
| Adebajo Ltd | London | 2022 |
| Adebanke Tade Limited | St. Albans | 2014 |
| Adebayo Ventures Ltd | Dartford | 2025 |
| Adec Limited | London | 1999 |
| Adec Property Consultants Ltd | Burton-On-Trent | 2021 |
| Adeca Engineering Limited | Aberdeen | 2011 |
| Adeca Ltd | Barnsley | 2013 |
| Adecan Services Limited | Coventry | 2011 |
| Adecaro | Wigan | 2025 |
| Adeche Design Ltd | London | 2026 |
| Adeco Alliance Development Company Limited | Horley | 1997 |
| Adecoe Limited | London | 2013 |
| Adectio Ltd | Fulbourn | 2018 |
| Adecyn Care Services Ltd | Birmingham | 2006 |
| Adedapo Advisory Ltd | London | 2025 |
| Adedeji Capital Ltd | London | 2018 |
| Adeditorial Ltd | Bedford | 2013 |
| Adedola Limited | London | 2023 |
| Adedunni Limited | London | 2019 |
| Adeeb Facilities Management Limited | South Croydon | 2020 |
| Adeevo Limited | Barnet | 2005 |
| Adefioye Consultancy Limited | London | 2012 |
| Adegas Advisory Ltd | London | 2024 |
| Adegrity Ltd | Stirling | 2022 |