| AU Bullion’S Ltd | Oldham | 2022 |
| AU Creative Ltd | Birmingham | 2017 |
| AU Customs Ltd | Bury St. Edmunds | 2023 |
| AU Design Ltd | Wolverhampton | 2016 |
| AU Gold Beds Ltd | Batley | 2020 |
| AU Goldsmith Ltd | Manchester | 2025 |
| AU Gourmand Boulangerie Ltd | Edinburgh | 2018 |
| AU Gourmand Limited | | 2003 |
| AU Jewels & Co Ltd | Peacehaven | 2024 |
| AU Petit Biscuit Limited | London | 2021 |
| AU Processing Ltd | London | 2024 |
| AU Pure Castings Ltd | Hounslow | 2026 |
| Au-Chemi Ltd | Cardiff | 2020 |
| Au-Cu Refining Ltd | Leven | 2025 |
| Au-Lux Ltd | London | 2023 |
| Au-Yeung and Tsang Holding Limited | Peterborough | 2025 |
| AU2MAC Limited | Bacup | 2025 |
| Auberon Group Limited | London | 2026 |
| Aubert Plant Nutrition Co., Ltd. | London | 2024 |
| Aubic Sales (Brighton) Limited | Littlehampton | 1975 |
| Aubin Limited | Aberdeen | 1986 |
| Aubrey Aerospace Technology Co., Ltd | West Midlands | 2022 |
| Aubrey Fragrance Ltd | Manchester | 2025 |
| Auchengate Pallet Manufacturer Ltd | Irvine | 2025 |
| Auchenkilns Brewery Limited | Glasgow | 2019 |
| Auckland Cycle Works Ltd | Bishop Auckland | 2023 |
| Auckland Manufacturing Ltd | Stevenage | 2013 |
| Auckland Race Trux Limited | Cardiff | 2002 |
| Auckland Sheet Metal Limited | Bishop Auckland | 1999 |
| Aucorde Ltd | London | 2025 |
| Auction REG Ltd | London | 2025 |
| Audacious Automotive Ltd | Bathgate | 2025 |
| Audacious Marine Boats and Mouldings Limited | Ramsgate | 2019 |
| Audacious Marine Limited | Ramsgate | 2012 |
| Audacious Marine Services Ltd | Beaumaris | 2018 |
| Audax Global Solutions Limited | Plymouth | 2007 |
| Audax Solutions Ltd | Plymouth | 2013 |
| Audaychi Limited | London | 2024 |
| Auddr.Ai Ltd | London | 2025 |
| Aude Holdings Limited | London | 2023 |
| Aude London Limited | London | 2022 |
| Audeeo Innovations Limited | London | 2011 |
| Audel Tech Limited | Westhill | 2010 |
| Audeltra Ltd | London | 2026 |
| Auden Funeral Supplies Limited | Liversedge | 1999 |
| Auden Mckenzie (Pharma Division) Limited | Castleford | 1999 |
| Audere Pure Limited | Maidenhead | 2026 |
| Auderesemper Ltd | London | 2022 |
| Audessence Limited | Haywards Heath | 2005 |
| Audiac Audio Ltd | Bristol | 2018 |
| Audible Spaces Limited | London | 2015 |
| Audicare Ltd | London | 2019 |
| Audicon International Limited | London | 2025 |
| Audience Systems Limited | Westbury | 1972 |
| Audience Upholstery Ltd | Westbury | 2017 |
| Audient Limited | Basingstoke | 1997 |
| Audifresh Ltd | London | 2023 |
| Audio by Alex Ltd | London | 2025 |
| Audio Cabinet Construction Ltd | Weston-Super-Mare | 2010 |
| Audio Chic Limited | Skipton | 2021 |
| Audio Circuits UK Ltd | Burnley | 2020 |
| Audio Computer Ltd | Oxford | 2023 |
| Audio Correction Ltd | Burnley | 2022 |
| Audio Definition Limited | Worcester | 2006 |
| Audio Design Services Limited | Higher Hillgate | 1990 |
| Audio Division Ltd | Ilkley | 2017 |
| Audio Electronics Ltd | Bracknell | 2019 |
| Audio Fidelity Records Inc Ltd | London | 2016 |
| Audio Fraternity Ltd | Farnborough | 2019 |
| Audio Gluttony Limited | Darvel | 2025 |
| Audio Guestbook Ltd | Gainsborough | 2021 |
| Audio Holdings Ltd | London | 2021 |
| Audio Innovations Limited | London | 1996 |
| Audio Input Ltd | Altrincham | 2023 |
| Audio Limited | Watford | 1947 |
| Audio Logistics VA Ltd. | Sunderland | 2000 |
| Audio Maintenance Limited | Bury | 2002 |
| Audio Note (UK) Limited | Horsham | 2003 |
| Audio Outpost Ltd | Biggleswade | 2017 |
| Audio Outsource Ltd | Dundee | 2019 |
| Audio Partnership PLC | London | 1994 |
| Audio Related Technology Limited | St. Albans | 2000 |
| Audio Repli-Tech Limited | Southampton | 2025 |
| Audio Resurgence Ltd | Fareham | 2025 |
| Audio Squadron Ltd | Colindale | 2019 |
| Audio Visual Commodity Ltd | Colchester | 2003 |
| Audio Visual Facilities Maintenance Ltd | High Wycombe | 2011 |
| Audio Visual Impact Limited | Carlisle | 2013 |
| Audio Visual Services Ltd | Eastbourne | 2017 |
| Audio Visual Sheet Metal Limited | Milton Keynes | 2000 |
| Audio Visual Technical Support Services Ltd | Newton Abbot | 2015 |
| Audio Wave Limited | Westcliff-On-Sea | 2007 |
| Audio Wireless Limited | Hemel Hempstead | 2009 |
| Audio With Intelligence Limited | Ormskirk | 2022 |
| AUDIO3 Ltd | London | 2007 |
| Audiobricks Limited | Redruth | 2004 |
| Audiocircus Limited | Henfield | 2001 |
| Audioimpulse Limited | Filey | 2025 |
| Audioline Productions Limited | Kenley | 2025 |
| Audiophile Digital Optical Technology Limited | Farnham | 2022 |