| AGG Investment Group Limited | Birmingham | 2021 |
| Aggies Vipooches Ltd | Potters Bar | 2025 |
| Aggregate Intelligence Limited | Wantage | 2020 |
| Aggresso Physiotherapy & Rehab Clinic Ltd | West Bromwich, | 2021 |
| Aggyfuffandme Limited | Cardiff | 2024 |
| Aggz Limited | London | 2014 |
| AGH Property Services Limited | St. Helens | 2024 |
| Agha Barber Ltd | Salisbury | 2025 |
| Agha CUT Ltd | Glasgow | 2023 |
| Agha Motor Associates Limited | Epsom | 2018 |
| Aghaloo & Blackwater Community Association Ltd | Aughnacloy, | 2012 |
| Aghanloo Community Association | Limavady | 2014 |
| Aghapy TV Limited | New Malden | 2005 |
| Agid Ltd | Wembley | 2010 |
| Agifm Ltd | Wolverhampton | 2019 |
| Agile & Fit Limited | London | 2024 |
| Agile Conditioning Ltd | Northampton | 2019 |
| Agile Cyber Solutions Ltd | Dartford | 2012 |
| Agile Energy Recovery (Inverurie) Limited | Aberdeen | 2014 |
| Agile Global Logistics Group Ltd | Whiteley, Fareham | 2017 |
| Agile Health Group Ltd | Cardiff | 2022 |
| Agile Infrastructure Management Ltd | Bathgate | 2022 |
| Agile Project Resources Ltd | Cardiff | 2019 |
| Agile Pulse Limited | Datchet | 2023 |
| Agile Technoserve Limited | London | 2006 |
| Agile Training Plus Ltd | Wimborne | 2021 |
| Agile Treatments Limited | Bristol | 2025 |
| Agilitas Bidco Limited | Newcastle Upon Tyne | 2020 |
| Agilitas Human Investment Services Limited | London | 2022 |
| Agilitas Midco Limited | Newcastle Upon Tyne | 2020 |
| Agilitas Private Equity Services Limited | London | 2017 |
| Agilitas Topco Limited | Newcastle Upon Tyne | 2020 |
| Agility Consultancy Services Limited | Warrington | 2017 |
| Agility Experts Limited | Luton | 2017 |
| Agility Healthcare Ltd | Worthing | 2011 |
| Agility Life Sciences Limited | Nottingham | 2012 |
| Agility Nexus Limited | Ardley | 2023 |
| Agility Sports Products Limited | Milton Keynes | 1964 |
| Agility Wise Ltd | Banbury | 2016 |
| Agius Financial Solutions Ltd | Leigh-On-Sea | 2024 |
| Agius Property Services Ltd | South Croydon | 2026 |
| Agiv Limited | Crowthorne | 2025 |
| AGK Eco Energy Ltd | Bolton | 2019 |
| AGK R US Ltd | Shefford | 2007 |
| AGL Base Limited | Ilford | 2014 |
| Aglaea Hair London Limited | London | 2019 |
| Aglaia Limited | Lytham St Annes | 2004 |
| Aglow Group Ltd | Scunthorpe | 2022 |
| Aglowrad Services Limited | London | 2009 |
| AGM Business Development Limited | Stockport | 2015 |
| AGM IT Solutions Limited | Middlesbrough | 2015 |
| AGM Limited | Weston-Super-Mare | 1992 |
| AGM Procurement Limited | Sutton Coldfield | 2010 |
| AGM Sports Limited | London | 2023 |
| Agm&M Limited | Ellesmere Port | 2023 |
| Agmar Aquatic Imports Ltd | | 2003 |
| Agmk International Limited | London | 2015 |
| AGN 1466 Ltd | London | 2025 |
| AGN Bernadette C.I.C. | Romford | 2022 |
| AGN International - Emea Limited | London | 2002 |
| AGN International - West Asia & Africa Ltd | London | 2005 |
| AGN International Ltd | London | 1995 |
| AGN Ltd | London | 2006 |
| Agna Wellness Ltd | Stirling | 2025 |
| Agnej World Ltd | South Ockendon | 2015 |
| Agnelli's Governance Ltd | London | 2018 |
| Agnes & Pavel Ltd | Sutton | 2026 |
| Agnes Beauty Garden Ltd | London | 2025 |
| Agnes DOS Santos Ltd | Eastbourne | 2016 |
| Agnes Hair Care Ltd | Watford | 2020 |
| Agnes Khan Mentoring Ltd | London | 2023 |
| Agnes Permanent Ltd | Barking | 2022 |
| Agnes Services Limited | Peterborough | 2022 |
| Agnes Tattoo Ltd | Doncaster | 2025 |
| Agnieszka Plawska Dietetyk Psychodietetyk Ltd | Poole | 2024 |
| Agnitio Consulting Ltd | Hale | 2021 |
| Agnosco Consulting Limited | Lutterworth | 2012 |
| Agnostic Scotland Ltd. | Edinburgh | 2019 |
| AGO Nationwide Ltd | Coventry | 2017 |
| Agora Collective Limited | London | 2024 |
| Agora Competitions Ltd | Manchester | 2026 |
| Agora Consulting Services Limited | Warwick | 2022 |
| Agora Holdings Limited | Warwick | 2022 |
| Agora Rock Ltd | Surbiton | 2025 |
| Agoriad Cyfyngedig | Bangor | 1992 |
| Agoriad Training Cyfyngedig | Bangor | 1995 |
| Agorin Ltd | Glasgow | 2026 |
| Agoro Services Ltd | London | 2019 |
| Agoy Limited | London | 2018 |
| AGP AGP Ltd | Stoke-On-Trent | 2025 |
| AGP Conseil International Limited | London | 2017 |
| AGP Solution Ltd | Huddersfield | 2023 |
| AGR Brown Enterprises Limited | Stockport | 2025 |
| AGR Homes Limited | Southall | 2024 |
| Agreen Ltd | Glasgow | 2025 |
| Agri Business Limited | Haverhill | 1997 |
| Agri Compliance Consultants Limited | Aberystwyth | 2022 |
| Agri Merchants Limited | Hythe | 2021 |
| Agri Soil Services Limited | Peterborough | 2024 |
| Agri-Accessories Limited | Carlisle | 2012 |