| Adventure Getaways Ltd | York | 2025 |
| Adventure Global Limited | London | 2022 |
| Adventure Hires NE Ltd | Newcastle Upon Tyne | 2024 |
| Adventure Leadership Training Trust | Newry | 2004 |
| Adventure Legends Ltd | Carnforth | 2025 |
| Adventure Lifesigns Limited | London | 2000 |
| Adventure Medical Limited | Bakewell | 2010 |
| Adventure Orkney Tours Ltd | St Ola | 2026 |
| Adventure Peaks Limited | Ambleside | 2000 |
| Adventure Peaks Property Limited | Ambleside | 2018 |
| Adventure Philanthropy Limited | Leeds | 2014 |
| Adventure Quest (Great Bridge) Ltd | Stourbridge | 2017 |
| Adventure Residentials Ltd | Cardiff | 2019 |
| Adventure Resources Limited | Hull | 2009 |
| Adventure Roads Limited | London | 2019 |
| Adventure South America Motorcycling Limited | Heathfield | 2017 |
| Adventure Tails Limited | Leigh On Sea | 2017 |
| Adventure Tours U.K. Ltd | Wrexham | 2018 |
| Adventure Travel Networking Ltd | Hampton | 2019 |
| Adventure Vans Ltd | Doncaster | 2021 |
| Adventure Wild Safaris Limited | Whissendine | 2010 |
| Adventure With LIV Ltd | Trowbridge | 2025 |
| Adventure Wolf Ltd | Willenhall | 2024 |
| Adventure Women UK Ltd | Mildenhall | 2026 |
| ADVENTURE360 Ltd | London | 2011 |
| Adventureholidaycentre Ltd | Knutsford | 2014 |
| Adventures - Scotland Ltd | Motherwell | 2018 |
| Adventures After Teaching Ltd | Budleigh Salterton | 2023 |
| Adventures Await Travel Ltd | London | 2023 |
| Adventures by AJM Ltd | Aberdeen | 2025 |
| Adventures by Ltd | Uckfield | 2021 |
| Adventures by Wanderfuel Ltd | Hove | 2026 |
| Adventures for Students Limited | Pudsey | 2017 |
| Adventures Hub Ltd | London | 2024 |
| Adventures in Content Ltd | Woodbridge | 2014 |
| Adventures in Golf (UK) Limited | St. Andrews | 2007 |
| Adventures in Motion Ltd | Tunbridge Wells | 2017 |
| Adventures in Pharma Ltd | London | 2025 |
| Adventures in Utopia Limited | Hockley | 2017 |
| Adventures Limited | Pinner | 1999 |
| Adventures Overland UK Limited | London | 2025 |
| Adventuresholic Ltd | Liverpool | 2018 |
| Adventuretoursnowdonia Ltd | Colwyn Bay | 2018 |
| Adventurex Conferences C.I.C. | Cannock | 2023 |
| Adventurex Education Limited | London | 2025 |
| Adventuriada Ltd | Leeds | 2024 |
| Adventurine Limited | Swindon | 2003 |
| Adventurous Appetites Limited | Exeter | 2003 |
| Adventurous Journeys UK Ltd | London | 2022 |
| Adventurous Spending Club Ltd | London | 2024 |
| Advenus Healthcare Ltd | London | 2023 |
| Adversa Recruitment Limited | Hitchin | 2017 |
| Adversarial Aesthetics London Ltd | London | 2022 |
| Advert Mentor Limited | Cardiff | 2022 |
| Advertage Ltd | London | 2025 |
| Advertising Online Limited | St. Neots | 1999 |
| Advertising Resources Limited | Stockport | 1994 |
| Advest Capital Management Limited | Solihull | 2015 |
| Advex Solutions Ltd | St. Helens | 2025 |
| Advi Services Limited | Spalding | 2025 |
| Advice and Guidance Business Development Ltd | London | 2025 |
| Advice and Innovation Ltd | London | 2012 |
| Advice Bureau Plus Limited | Barnstaple | 2009 |
| Advice Help Bureau Limited | Eastbourne | 2026 |
| Advice in Media Limited | London | 2004 |
| Advice Infrastructure Ltd | Glasgow | 2012 |
| Advice NI | Newtownbreda, Belfast | 2009 |
| Advice Services Skeoge Ltd | Derry | 2021 |
| ADVICE4BUSINESS North East Ltd | Morpeth | 2013 |
| ADVICE4RISK Ltd | London | 2014 |
| ADVICE4TRAINING Centre Limited | Leicester | 2019 |
| Adviceair Limited | Northampton | 2001 |
| Adviced Cleaners Limited | London | 2023 |
| Advicesmith Ltd. | London | 2015 |
| Advicetrade Limited | Macclesfield | 2020 |
| Advicewise Investments Ltd | Seven Kings | 2017 |
| Advico Technology UK Limited | Chelmsford | 2017 |
| Advinia Health Care Partners Limited | London | 2011 |
| Advintage Limited | Whitley Bay | 2010 |
| Advise HR Limited | Kington | 2015 |
| Advise Media Consulting Limited | London | 2024 |
| Advise Tree Limited | London | 2020 |
| Adviserasset Limited | London | 2012 |
| Adviserfinder Ltd | London | 2026 |
| Adviserpay Limited | Leamington Spa | 2024 |
| Advision (Services) Ltd | Gerrards Cross | 2013 |
| Advision Security Ltd | Gerrards Cross | 2004 |
| Advisionary Ltd | London | 2021 |
| Advisoring London F&T Limited | London | 2016 |
| Advisory by Cutting Ltd | Wrotham Heath | 2022 |
| Advisory Gems Limited | London | 2014 |
| ADVISORY4PACK Ltd | Ashbourne | 2022 |
| Advisorylondon Limited | London | 2015 |
| Advisyo International Limited | London | 2018 |
| Advo Limited | Maidstone | 2001 |
| Advo One Limited | Maidstone | 2001 |
| Advoaid Consult Ltd | Rainham | 2025 |
| ADVOC8SE Global Ltd | Weybridge | 2025 |
| ADVOCA8 UK Limited | Cardiff | 2017 |
| Advocacy & Interaction Limited | Liverpool | 2011 |