| After Moment London Ltd | London | 2024 |
| After Rain Ltd | Northampton | 2024 |
| After Sales Services Limited | Merseyside | 1988 |
| After the Antique Limited | Thetford | 1996 |
| Afterbeat Coffee Ltd Ltd | Bridgend | 2023 |
| Afterchange Limited | Nantwich | 1993 |
| Afterlife Composites Limited | London | 2025 |
| Aftermath BJJ Knowle Ltd | Bristol | 2020 |
| Afternoon Paws Ltd | Wokingham | 2019 |
| Afterprint Ltd | Warrington | 2019 |
| Aftershock Prints Ltd | Llandrindod Wells | 2017 |
| Afton Chemical Limited | Berkshire | 1975 |
| Aftr Limited | Beckenham | 2021 |
| Aftrak Ltd | Sheffield | 2024 |
| AFU Namb Ltd | Grays | 2023 |
| Afuera Ltd | London | 2022 |
| AFV Holdings Ltd | Bolton | 2024 |
| AFV SIM Ltd | Great Gransden | 2005 |
| AFW Electrical Ltd | Strathaven | 2018 |
| AFX Mixing and Pumping Technologies Limited | Poole | 2015 |
| Afxx Ltd | Glasgow | 2013 |
| Afya Essence Ltd | Leicester | 2025 |
| Afya Lafia Innovations Ltd | Sheffield | 2025 |
| Afzal Garments Ltd | Leicester | 2022 |
| Afzal Pharma Ltd | Coventry | 2014 |
| AG & C Limited | Leighton Buzzard | 2019 |
| AG 20061 Ltd | Edinburgh | 2026 |
| AG Aviation Elite Ltd | Horsham | 2025 |
| AG Bakery Limited | Chessington | 2025 |
| AG Bespoke Ltd | Nottingham | 2024 |
| AG Brickwork Limited | London | 2025 |
| AG Bulider Ltd | Hornchurch | 2025 |
| AG Cakes Limited | Barking | 2025 |
| AG Catering Equipment Services Ltd | Ottery St. Mary | 2018 |
| AG Class Construction Limited | Basildon | 2026 |
| AG Components Ltd | London | 2026 |
| AG Composites Ltd | Royston | 2022 |
| AG Controls Ltd | Stanley | 2018 |
| AG Creative Designer Ltd | London | 2020 |
| AG Electrical Solutions Ltd | Bishop Auckland | 2020 |
| AG Fine Foods Limited | Glasgow | 2024 |
| AG Future Innovations Limited | Northampton | 2025 |
| AG Gases and Equipment Ltd | London | 2017 |
| AG Group Limited | Sheffield | 1981 |
| AG Inspections Ltd | Cambridge | 2025 |
| AG Instruments Limited | Leamington Spa | 2009 |
| AG Jewellery Limited | Woodford Green | 2025 |
| AG Joinery & Building Maintenance Ltd | Halifax | 2022 |
| AG Kombucha Ltd | London | 2025 |
| AG Locksmiths Limited | Saltash | 2012 |
| AG Locum Pharmacy Services Limited | Edinburgh | 2025 |
| AG Machinery Ltd | Mayfield | 2024 |
| AG Machinetech Ltd | Weston-Super-Mare | 2024 |
| AG Meridian Joinery Group Ltd | Waltham Abbey | 2026 |
| AG Meridian Joinery Limited | Waltham Abbey | 2016 |
| AG Mold Joinery Ltd | Rainham | 2026 |
| AG Motorsport Development Ltd | Leiston | 2025 |
| AG Mowers Ltd | London | 2025 |
| AG Printing Ltd | Grantham | 2025 |
| AG Property Services EA Ltd | Lowestoft | 2022 |
| AG Quick Service Limited | Hemel Hempstead | 2011 |
| AG Rotor Support Ltd | Witney | 2026 |
| AG Servicing Limited | West Midlands | 2004 |
| AG Surface Repair Specialist Ltd | Worcester | 2022 |
| AG Tech Services Ltd | Manchester | 2017 |
| AG Telecommunications Limited | Liverpool | 2010 |
| AG UK Art Limited | Newcastle Upon Tyne | 2023 |
| AG Welding Services Ltd | Shotts | 2025 |
| AG Windows Supplies Limited | Coventry | 2023 |
| Ag's Candy Factory Ltd | Liverpool | 2020 |
| Ag's Candy Ltd | Liverpool | 2018 |
| Ag-Con Products Limited | Newry | 2001 |
| AG7 Construct Ltd | Manchester | 2022 |
| AGA Composites Ltd | Cambridge | 2023 |
| AGA Couture London Limited | Weybridge | 2019 |
| AGA Industry Ltd | Hexham | 2023 |
| AGA Installations Limited | London | 2017 |
| AGA Print Ltd. | Southend On Sea | 2003 |
| AGA Rangemaster Limited | Long Eaton | 1999 |
| AGA Stovemaster Ltd | Upminster | 2002 |
| Aga-Robotics Limited | Corby | 2024 |
| Again Again by Hannah Ltd | Barrow-In-Furness | 2025 |
| Again Ltd | Cardiff | 2026 |
| Again Technologies (Newry) Limited | Newry | 2021 |
| Against the Grain Cidery Ltd | London | 2019 |
| Against the Grain Joinery Limited | Hereford | 2003 |
| Against the Grain Spirits Ltd | Edinburgh | 2024 |
| Agalle Limited | Lanark | 2021 |
| Agamemnon Boatyard Ltd. | Lymington | 1998 |
| Agamemnon Limited | Bury St Edmunds | 2014 |
| Aganea Interiors Ltd | Harlow | 2021 |
| Agapai Ltd | London | 2020 |
| Agape Carpentry Ltd | Rochester | 2024 |
| Agape Communications Ltd | Belfast | 2008 |
| Agar & ASH Ltd | Batley | 2025 |
| Agar Limited | Worcester | 1975 |
| Agar's Restoration Limited | London | 2025 |
| Agaram Designs Ltd | Bicester | 2026 |
| Agaram Foods UK Ltd | Nottingham | 2025 |
| Agartom Limited | London | 2010 |