| Adio Technology Ltd | Epsom | 2020 |
| Adioma Consulting Limited | Warrington | 2021 |
| Adiona Design Limited | London | 2021 |
| Adiona Quantum Technologies Ltd | London | 2026 |
| Adiosc Consulting Limited | Altrincham | 2015 |
| Adipop Limited | Maidenhead | 2026 |
| Adiquoo Ltd | Buxton | 2020 |
| Adira Crown Advisory Ltd | South Ockendon | 2026 |
| Adira Investment Services Limited | Stockton On Tees | 2023 |
| Adiri Tech Ltd | Solihull | 2026 |
| Adirion Ltd | London | 2012 |
| Adirs Way Together Ltd | London | 2025 |
| Adiru Consulting Ltd | London | 2020 |
| Adis Legacy NON Profit CIC | Lincoln | 2022 |
| Adis.Engineers Ltd. | St Neots | 2014 |
| Adisa Ltd | Herne Bay | 2006 |
| Adiscc Limited | Oakham | 2024 |
| Adisha Enterprise Ltd | Gloucester | 2018 |
| Adiso Therapeutics Limited | Altrincham | 2021 |
| Adit Investment Limited | Liss | 2002 |
| Aditall Ltd | Dagenham | 2001 |
| Aditec Engineering Ltd | Liverpool | 2025 |
| Aditi Edhas Ltd | Haywards Heath | 2020 |
| Aditi Trustees Limited | Barking | 2023 |
| Aditiv Ltd | Andover | 2024 |
| Aditup Ltd | Uckfield | 2020 |
| Aditus Architectural Services Limited | Carlisle | 2016 |
| Aditus Limited | St. Albans | 1999 |
| Adityaraj DEV Limited | Leamington Spa | 2021 |
| Adiuta Ltd | London | 2024 |
| Adiutare International Ltd | Gerrards Cross | 2018 |
| Adiuvare Leisure Limited | Chipstead | 2020 |
| Adiuvare Solutions Ltd | Abergavenny | 2021 |
| Adiuvex Ltd | Wirral | 2007 |
| Adiuvo Consultancy Ltd | Southampton | 2024 |
| Adiuvo Engineering & Training Ltd | Harlow | 2014 |
| Adiuvo Family Law Ltd | Kings Cross | 2025 |
| Adiuvo Limited | York | 2004 |
| Adiva Accountants Ltd | Bromley | 2015 |
| Adiva Catering Limited | Bedford | 2021 |
| Adiva Inc Limited | Eastleigh | 2025 |
| Adiva Limited | Bracknell | 2024 |
| Adivabo Ltd | Cirencester | 2026 |
| Adivis Ltd | London | 2020 |
| Adivo Capital Partners Ltd | London | 2026 |
| Adivo Ltd | London | 2023 |
| Adivox Limited | Southall | 2025 |
| Adix International Ltd | London | 2015 |
| Adixon Limited | Shrewsbury | 2016 |
| Adiyan System Solutions Limited | Birmingham | 2025 |
| ADJ Architects Ltd | Tenbury Wells | 2017 |
| ADJ Architectural Services Limited | Wellingborough | 2012 |
| ADJ Business Solutions Ltd | London | 2011 |
| ADJ Calculations Ltd | Prenton | 2021 |
| ADJ Consulting Ltd | Ilkley | 2023 |
| ADJ Electrics Ltd | Bishopton | 2018 |
| ADJ KMN PRS Global Ventures Ltd | Eat Ham | 2020 |
| ADJ Law Limited | London | 2018 |
| ADJ Mgmt Ltd | Harlow | 2022 |
| ADJ Phils Management Limited | Basildon | 2010 |
| ADJ Surfacing & Consultancy Limited | Doncaster | 2017 |
| ADJ Surveying Ltd | Swansea | 2024 |
| ADJ Technical Ltd | Derby | 2011 |
| Adjacency Group Ltd | Northampton | 2016 |
| Adjacent Consulting Limited | Farnborough | 2014 |
| Adjacent Group Limited | Banbury | 2022 |
| Adjacent Ltd | Chipping Campden | 2018 |
| Adjanic Limited | Bedford | 2025 |
| Adjanor & Associates Limited | London | 2013 |
| Adjaye/Associates Limited | London | 2002 |
| Adjective Noun Ltd | London | 2024 |
| Adjefils Sport Marketing Ltd | London | 2022 |
| Adjoin Studio Ltd | London | 2019 |
| Adjoint Labs Limited | Oxford | 2025 |
| Adjomat Consulting Limited | Worcester | 2017 |
| Adjudication and Arbitration Services Limited | Hockley | 2024 |
| Adjudication Limited | Horsham | 2003 |
| Adjudication Solutions Limited | Cranfield | 2014 |
| Adjudix Limited | Chepstow | 2024 |
| Adjuice SEO Services Ltd | Camberley | 2007 |
| Adjust Procurement Solutions Limited | Bristol | 2003 |
| Adjust Software Limited | Watford | 2012 |
| Adjust Ventures CIC | Sheffield | 2024 |
| Adjustability Consulting Limited | Offley | 2016 |
| Adjutant MTC Limited | Guildford | 2002 |
| Adjuvant Coaching & Consulting Limited | Romford | 2024 |
| Adjuvantyx Ltd | Tonbridge | 2018 |
| Adjuvo Consulting Ltd | Virginia Water | 2018 |
| Adjuvo Energy Limited | Stamford | 2013 |
| Adjuvo Group Limited | Redditch | 2011 |
| Adjw Limited | Sandwich | 2016 |
| ADK Accountancy Limited | Welling | 2017 |
| ADK Advertising Ltd | Ware | 2019 |
| ADK Business Consulting Ltd | London | 2013 |
| ADK Business Ltd. | London | 2016 |
| ADK Capital Investments Ltd | Bournemouth | 2025 |
| ADK Consortium (UK) Limited | London | 2025 |
| ADK Consultancy Ltd | Kidlington | 2013 |
| ADK Consulting Ltd | Hemel Hempstead | 2006 |
| ADK Environmental Management Limited | Preston | 2005 |