| ADD 3D Solutions Ltd | Grange-Over-Sands | 2023 |
| ADD an Apron Ltd | Cardiff | 2025 |
| ADD Good Design Ltd | Margate | 2024 |
| ADD Industries Limited | Pool | 2003 |
| ADD Mobility Ltd | Warrington | 2022 |
| ADD Power Limited | High Wycombe | 2022 |
| Add-Mech Ltd | Northampton | 2022 |
| Adda Co NE Ltd | Jarrow | 2020 |
| Addacabin Limited | Kilmarnock | 2019 |
| Addagrip Terraco Ltd | Uckfield | 1980 |
| Addalogouk Limited | Swindon | 2024 |
| Addaptx Ltd | Nuneaton | 2024 |
| Addasu Engineering Ltd | Bristol | 2025 |
| Addaw’I Limited | London | 2024 |
| Added Security Technology Limited | Portchester | 1995 |
| Added Value Hub Ltd | London | 2025 |
| Addeng Limited | Hastings | 2024 |
| Adder Ltd | Leicestershire | 2003 |
| Adder Screen Print Limited | Hinckley | 1983 |
| Adder Technology Limited | Leicester | 1984 |
| Adderley Ceramics Limited | Stoke On Trent | 2001 |
| Adders Entertainment Group Ltd | Bury St. Edmunds | 2024 |
| Addev Materials Aerospace Limited | Poole | 2002 |
| Addfield Environmental Systems Limited | Burntwood | 2008 |
| Addfield Limited | Cannock | 2014 |
| Addfield Projects Limited | Burntwood | 2021 |
| Addform Limited | Liverpool | 2012 |
| Addica Limited | Bromsgrove | 1969 |
| Addicott Electrics Limited | Exeter | 1987 |
| Addifab Limited | London | 2020 |
| Addinall Interiors Limited | York | 2019 |
| Addingford Engineering Limited | Wakefield | 2022 |
| Addiscott Ltd | Verwood | 2014 |
| Addison Engineering Company (Hillhouse) Limited | Thornton Cleveleys | 1996 |
| Addison Forming Technologies Limited | Warrington | 2012 |
| Addison Media Limited | Wragby | 2023 |
| Addison MOT Centre Limited | Gateshead | 2017 |
| Addison Print Limited | Northampton | 2013 |
| Addison Technology Limited | London | 2020 |
| Addition Design Ltd | Wirral | 2017 |
| Additions Mobile Accessories Limited | Carlisle | 2004 |
| Additiva Limited | New Romney | 2026 |
| Additive - X Limited | Ripon | 1988 |
| Additive First Limited | Alton | 2021 |
| Additive Intelligence Limited | Newcastle Upon Tyne | 2020 |
| Additive Manufacturing Centre of Excellence Ltd | Derby | 2021 |
| Additive Manufacturing Solutions Ltd. | Burscough | 2017 |
| Additivity Limited | London | 2014 |
| Addlestone Electronics Limited | Bisley, Woking | 1964 |
| Addlestone Tyre Centre Ltd | Addlestone | 2025 |
| Addlestone Tyre Services Ltd | Addlestone | 2025 |
| Addlestone Tyres Ltd | Addlestone | 2023 |
| Addley Motors Ltd | Harrogate | 2023 |
| Addlite Limited | Walsall | 2016 |
| Addlux Limited | Alton | 2010 |
| Addmail Solutions Limited | Burnley | 2019 |
| Addmaster (U.K.) Limited | Beaconside | 2000 |
| Addmix Concrete Limited | Warrington | 2012 |
| Addmore Engineering Limited | Northampton | 1999 |
| Addo Food Group (Holdings) Ltd | 1-4 Cumberland Place | 2017 |
| Addo Food Group Limited | Nottingham | 2006 |
| Addparts Ltd | Sheffield | 2024 |
| Addurn Ltd | Ruislip | 2020 |
| Addvantage Global Limited | London | 2017 |
| Addvent Air Systems Limited | Birkenhead | 1986 |
| Addware Industries Limited | Luton | 2026 |
| Addworks Printing Solutionts Ltd | Hounslow | 2026 |
| Addx International Ltd | Belfast | 2019 |
| Addy Traders Ltd | Maidenhead | 2025 |
| ADE Cookson Precision Engineering Ltd | Sandbach | 2026 |
| ADE Kiresci Engineering Limited | Northwich | 2018 |
| ADE Trading Limited | Rickmansworth | 2014 |
| Adebabs Ltd | London | 2019 |
| Adebola Ventures Limited | London | 2020 |
| Adec Marine Limited | Surrey | 1984 |
| Adee Engineering (Fabrications) Ltd | Sheffield | 2003 |
| Adeeb Sons and Co Ltd | Hounslow | 2025 |
| Adeel Communications Ltd | Edinburgh | 2021 |
| Adeero Ltd | London | 2021 |
| Adeiladwaith Ebeneser CYF | Caernarfon | 2019 |
| Adekaz Limited | Coventry | 2019 |
| Adel Construction and Civil Engineering Ltd. | Hayes | 2017 |
| Adel Equipment Management Limited | Manchester | 2023 |
| Adela Axuni E.U. Ltd | London | 2016 |
| Adela Kiel Ltd | Cardiff | 2026 |
| Adelaide Engineering Company Limited | Walsall | 1960 |
| Adelaide Sauces Limited | Northampton | 2021 |
| Adelan Limited | Atherstone | 1996 |
| Adelante Joinery Limited | Clydebank | 2023 |
| Adelantees Ltd | Glasgow | 2023 |
| Adelco Screen Process Limited | Bordon | 1972 |
| Adele Rosie Fine Jewellery Limited | Fleet | 2026 |
| Adeli Clothing Co., Ltd | Coventry | 2022 |
| Adeline Waterson Ltd | Wakefield | 2024 |
| Adelmi Ltd | Craigavon | 2020 |
| Adelphi Distillery (1826) Limited | Acharacle | 2010 |
| Adelphi Distillery Limited | Acharacle | 1992 |
| Adelphi Engineering & Construction Limited | Lugar | 1998 |
| Adelphi Graphics Limited | London | 1977 |
| Adelphi Manufacturing Company,Limited | Haywards Heath | 1947 |