| Advanced-Metering Ltd | Lancaster | 2022 |
| Advanced-Passive Thermal Solutions Ltd | Rochester | 2025 |
| ADVANCED3DPS. Ltd | Blackburn | 2024 |
| Advancedsashwindows Limited | Maidstone | 2018 |
| Advancing Client Engagement Ltd | Chelmsford | 2017 |
| Advanex Europe Limited | Southwell | 1988 |
| Advania Global Ltd | Blackburn | 2020 |
| Advanna Ltd | Chorley | 2026 |
| Advanta Group Limited | Cwmbran | 2000 |
| Advantage Automotive Limited | Presteigne | 2012 |
| Advantage Catering Equipment Limited | Ashford | 2008 |
| Advantage Concrete Company Ltd | Epsom | 2006 |
| Advantage Cover Fabrications Limited | Thorpe Waterville | 2003 |
| Advantage Digital Print Limited | Dorchester | 2014 |
| Advantage Door and Kitchen Limited | London | 2024 |
| Advantage Engineering Solutions Ltd | Nottingham | 2005 |
| Advantage Fabrication Limited | Lancaster | 2003 |
| Advantage Feeders UK Limited | Shrewsbury | 2012 |
| Advantage Print and Promotions Limited | Sheffield | 2009 |
| Advantage Printroom Ltd | Bracknell | 2001 |
| Advantage SIX Limited | Bramhall | 2003 |
| Advantage Utilities Services Limited | Gateshead | 2006 |
| Advantage Westech Limited | Stoke On Trent | 1998 |
| Advantis Control Solutions Limited | Bristol | 2012 |
| Advantis Global Ltd | Pinner | 2018 |
| Advantura Limited | St. Helens | 2023 |
| Advanz Pharma Generics (UK) Limited | London | 1992 |
| Advartex Leisurewear Limited | East Sussex | 2004 |
| Advartex Limited | Ticehurst | 1977 |
| Advasign Printing Limited | Pentre | 2025 |
| Advatac Limited | Sutton In Ashfield | 2005 |
| Advatech Limited | Thetford | 2000 |
| Adven Inc. UK Ltd | London | 2025 |
| Advent Bioservices Ltd | Cambridge | 2013 |
| Advent Cover Limited | Glasgow | 1991 |
| Advent Plastics Limited | Wellingborough | 1959 |
| Advent Press Limited | High Wycombe | 2011 |
| Advent Technologies Limited | Selby | 2006 |
| Adventis CD UK Ltd | London | 2024 |
| Adventrix Ltd | Haywards Heath | 2024 |
| Adventura Designs Ltd | Freckleton | 2024 |
| Adventure Brands Ltd | York | 2018 |
| Adventure Clothing Limited | Bolton | 2021 |
| Adventure Furniture Limited | Wakefield | 2025 |
| Adventure Gear Co Ltd | Walkerburn | 2024 |
| Adventure Industries Ltd | Newton Abbot | 2019 |
| Adventure KIT UK Limited | St Asaph | 2002 |
| Adventure Marine Limited | Lymington | 2020 |
| Adventure Pods & Services Ltd | Stockport | 2024 |
| Adventure Sport Services Ltd | Penrith | 2020 |
| Adventure Style Campers Ltd | Rugby | 2025 |
| Adventure Supply Company Limited | Flimwell | 2006 |
| Adventure Vehicles Limited | Twickenham | 2018 |
| Adventures and Play Ltd | Cowes | 2020 |
| Adverset Media Solutions Limited | London | 2002 |
| Advertiser Office Printers Limited | Normanton | 2021 |
| Advertising Technique Limited | Lytham St. Annes | 2006 |
| Advetec Holdings Limited | Trowbridge | 2007 |
| Advetec Leasing Limited | Trowbridge | 2015 |
| Advi Contractors Ltd | Dagenham | 2016 |
| Advics Culinary & Bakery Limited | London | 2026 |
| Advider Limited | Oldham | 2014 |
| Advik Technologies Limited | Birmingham | 2023 |
| Advion Ltd | Ipswich | 2001 |
| Advise-Deta Limited | Bedford | 2015 |
| Advita Ortho UK Limited | Redditch | 2004 |
| Advocate Brewing Co Limited | London | 2026 |
| ADW Applications & Service Limited | | 2006 |
| ADW Refrigeration Ltd | Market Drayton | 2026 |
| ADW Steelworks Ltd | Leigh-On-Sea | 2016 |
| ADW2016 Ltd | Porthcawl | 2016 |
| Adway Heat Pumps Ltd | Chelmsford | 2020 |
| Adwear Limited | Wimborne | 2000 |
| Adweld Fabrications Limited | Gosport | 2011 |
| Adwick Concrete Products Ltd | Doncaster | 2021 |
| Adwin Spring Company Limited | West Midlands | 1958 |
| Adwoa Doll Ltd | Highgate | 2021 |
| Adwoa's Cakes Ltd | Chadwell Heath | 2021 |
| Adws Global Limited | Royston | 2008 |
| Adxpressions Media Ltd | London | 2018 |
| Ady-K Marine Services Ltd | Freshwater | 2023 |
| Adymens Furniture Ltd | Northampton | 2026 |
| Adze & Froe Ltd | Glasgow | 2023 |
| Adze Heritage Carpentry & Joinery Ltd | Okehampton | 2025 |
| Adze Woodwork Ltd | Bedford | 2025 |
| Adzzzy's Armoury Ltd | Bognor Regis | 2025 |
| AE 2009 Limited | Leeds | 1979 |
| AE Air Technology Ltd | Beckenham | 2022 |
| AE Bakery Limited | Brentford | 2020 |
| AE Crane&Plant Hire Ltd | Blackpool | 2020 |
| AE Interiors Ltd | Huddersfield | 2022 |
| AE Jewelry Ltd | Hull | 2025 |
| AE Maintenance Ltd | Burnley | 2016 |
| AE Manufacturing Services Limited | Belfast | 2020 |
| AE Mixers Limited | Sandy | 1968 |
| AE Plant Repairs Limited | Castleford | 2022 |
| AE Precision Engineering Ltd | Salisbury | 2016 |
| AE Rubber (UK) Limited | Erdington | 2007 |
| AE Signs Studio Ltd | Rugby | 2023 |
| Ae&T Limited | Birmingham | 1997 |