| Auctionet UK Ltd | Westbury | 2019 |
| Auctus Holdings Ltd | London | 2022 |
| Audacious Church | Salford | 2008 |
| Audacity Hair Ltd | Cleethorpes | 2026 |
| Audalet Ltd | London | 2026 |
| Audax Property Limited | Shawbury | 2019 |
| Audhd Forward Ltd | Richmond | 2024 |
| Audible & Visual Security Limited | Solihull | 1989 |
| Audible Solutions Ltd | St. Neots | 2018 |
| Audic Ltd | Haverfordwest | 2019 |
| Audin Beauty Ltd | London | 2025 |
| Audin Homecare Limited | Huddersfield | 2001 |
| Audio Content Fund | Newcastle Upon Tyne | 2018 |
| Audio Inspired Running Ltd | Croydon | 2005 |
| Audio Producers Association | London | 2008 |
| Audio Solutions (North West) Limited | Bolton | 2004 |
| Audio Visual Logix Ltd | Bushey | 2011 |
| Audiocosm Ltd | Deeside | 2021 |
| Audioisland Limited | North East Lincolnshire | 2001 |
| Audiology Limited | Leeds | 2004 |
| Audiomaster Limited | Exeter | 2007 |
| Audiomotion Studios Limited | Oxford | 2002 |
| Audiovisual Anti-Piracy Alliance Limited | Corsham | 2012 |
| Audit Bureau of Circulations Limited | Berkhamsted | 1931 |
| Audit Partners Ltd | Chester | 2017 |
| Audit Point Limited | Wadebridge | 1992 |
| Audition Circle Limited | London | 2020 |
| Audley Cobham Management Limited | Egham | 2020 |
| Audley Cobham Rent Company Limited | Egham | 2020 |
| Audley Community Action Group. Papg C.I.C. | Stoke-On-Trent | 2024 |
| Audley Investments NO 1 Limited | Egham | 2019 |
| Audley Investments NO 2 Limited | Egham | 2019 |
| Audley Investments NO 3 Limited | Surrey | 2019 |
| Audley Investments NO 4 Limited | Surrey | 2019 |
| Audley Scarcroft 1 Rent Company Limited | Surrey | 2020 |
| Audley Scarcroft 2 Rent Company Limited | Surrey | 2020 |
| Audley Scarcroft Management Limited | Surrey | 2020 |
| Audley Sunningdale Park Management Limited | Surrey | 2019 |
| Audley Sunningdale Park Rent Company Limited | Surrey | 2019 |
| Audley Wealth Limited | Basildon | 2020 |
| Audra J Macphee Ltd | Hamilton | 2024 |
| Audrena Ltd. | Innerleithen | 2018 |
| Audrey Ametis Limited | London | 2017 |
| Audrey Campbell Hair Ltd | Hamilton | 2023 |
| Audrey QUA Hair Ltd | Glasgow | 2020 |
| Audrey's Fine Garment Care Ltd | Tunbridge Wells | 2025 |
| Audrey's Hair Salon Limited | Grenock | 2017 |
| Audrey's Salon Ltd | Manchester | 2025 |
| Audreys Laundry Ltd | Tunbridge Wells | 2020 |
| Audrie Woodhouse Honestly Speaking Limited | Malton | 2024 |
| Aufguss Limited | London | 2025 |
| AUG MS Ltd | London | 2012 |
| Augeo Autus Ventures (AAV) Ltd | Dartford | 2014 |
| Aughakillymaude Community Association | Enniskillen | 1990 |
| Aughnacloy Golf Properties Ltd | Co. Tyrone | 1998 |
| Aughnacloy Presbyterian Church Community Group | Aughnacloy | 2018 |
| Aughra's EYE Tattoo Parlour Ltd | Glasgow | 2019 |
| Aughton Head Spa Limited | Formby | 2025 |
| Aughton Properties Ltd | St Albans | 2003 |
| Aughton Wellness Limited | Ormskirk | 2024 |
| Aughtonstoves Limited | Lancaster | 2018 |
| Augment Yourself Ltd | Mauchline | 2018 |
| Augmented Human Intelligence Ltd. | London | 2023 |
| Augmented Management Solutions Limited | Rotherham | 2015 |
| Augmentum Ltd | Hook | 2023 |
| Augoe and Sons Ltd | London | 2013 |
| Augu's Palace Ltd | West Drayton | 2023 |
| Augural Ltd | Benfleet | 2019 |
| August & Piers Ltd | London | 2019 |
| August Consulting Group Ltd | Manchester | 2021 |
| August GPATC01 Limited | London | 2024 |
| August GPATC02 Limited | London | 2025 |
| August PATC02 Limited | London | 2023 |
| August PATC03 Limited | London | 2024 |
| August PATC04 Limited | London | 2024 |
| August PATC05 Limited | London | 2025 |
| August Prime 1 Limited | London | 2024 |
| August Robotics Limited | London | 2023 |
| August SC02 Limited | London | 2022 |
| August SC04 Limited | London | 2023 |
| August Sutton Limited | Preston | 2024 |
| Augusta Aiken & Associates Limited | London | 2018 |
| Augusta Capital Management Limited | Richmond | 2023 |
| Augusta IT Limited | Taunton | 2019 |
| Augustinians of the Assumption | London | 2011 |
| Augustus Solutions Midlands Ltd | Birmingham | 2023 |
| Aujen Limited | Birmingham | 2009 |
| AUK Inc Ltd | Romford | 2013 |
| Aukrathanapon Ltd | Swindon | 2017 |
| Auksánō Ltd | Leeds | 2024 |
| Auld Manse Ltd | Shetland | 2021 |
| Aulis Property Ltd | Leeds | 2019 |
| AUM (UK) Ltd | London | 2001 |
| AUM Consultancy PVT. Ltd | Oldbury | 2016 |
| AUM Crematorium Limited | Denham | 2024 |
| AUM Shanti Funeral Services Limited | Harrow | 2022 |
| AUM Wellness Limited | York | 2024 |
| Auma Beauty Ltd | London | 2024 |
| Aumbry Services Limited | Basildon | 2012 |
| Aumida Ltd | Basildon | 2018 |