| A Gray Consultancy Limited | Kilmarnock | 2025 |
| A Green Financial Services Ltd | London | 2019 |
| A Greencircle Engineering and Consulting Ltd | Aberdeen | 2025 |
| A Greener Earth Ltd | Dorking | 2021 |
| A Greener England Ltd | London | 2020 |
| A Greener Future (AGF) Ltd | Dudley | 2023 |
| A Gregory Consultancy Ltd | Barnsley | 2022 |
| A Grey Area Ltd | London | 2014 |
| A Grice Contracting Limited | Oxford | 2025 |
| A H & S Consultants Limited | Stowmarket | 2013 |
| A H (Taxis) Ltd. | Livingston | 1999 |
| A H - Biotech Limited | London | 2017 |
| A H Accountants Ltd | Nottingham | 2011 |
| A H and Associates Limited | London | 2015 |
| A H Assessors Limited | Leeds | 2022 |
| A H Bedford & SON Limited | Worcestershire | 1961 |
| A H Brooks Solicitors Limited | Leek | 2011 |
| A H Building and Maintenance Ltd | Canvey Island | 2018 |
| A H Consultancy (London) Ltd | Stockport | 2015 |
| A H Cross & Co Limited | Newport | 2004 |
| A H Designs Consultancy Limited | Luton | 2011 |
| A H Dore Limited | London | 2023 |
| A H Eventing Limited | Congleton | 2009 |
| A H Gravatt Limited | Reigate | 2006 |
| A H K Associates Limited | Redhill | 2002 |
| A H Management Consultancy Ltd | Keighley | 2025 |
| A H Marine Consultants Ltd | Colchester | 2025 |
| A H Martin Limited | Bexhill On Sea | 1995 |
| A H Mechanical Services Ltd | Blyth | 2025 |
| A H Orthopaedics Limited | Cambridge | 2011 |
| A H PIX Limited | South Yorkshire | 2005 |
| A H R Motorsport Services Ltd | Buckingham | 2016 |
| A H R Style Limited | Nottingham | 2017 |
| A H S Automotive Limited | Sheffield | 2014 |
| A H Sawyer Consulting Ltd | Bury St. Edmunds | 2018 |
| A H Surveying & Cost Consultancy Ltd | Clacton-On-Sea | 2014 |
| A H T Aviation Consultancy Limited | Stourbridge | 2017 |
| A Hadley Accounting Services Limited | Cradley Heath | 2014 |
| A Haemmerli Limited | London | 2015 |
| A Haider Ltd | Luton | 2019 |
| A Hall Marine Ltd | Plymouth | 2025 |
| A Halsall Ltd | London | 2024 |
| A Happy Place Limited | Leamington Spa | 2019 |
| A Harcourt Ltd | Stockport | 2012 |
| A Harding Ltd | Rochdale | 2023 |
| A Harlan Accounting Solutions Limited | Leicester | 2025 |
| A Harley Designs Ltd | Melbourne | 2020 |
| A Harvey Legal Limited | Brighton | 2025 |
| A Hayes Consulting Ltd | Stockport | 2025 |
| A Hayman Ltd | Derby | 2026 |
| A Head for Work Limited | Cambridge | 2008 |
| A Head Start Limited | Teddington | 2024 |
| A Heald Limited | Leeds | 1975 |
| A Heffs Ltd | Camberley | 2025 |
| A Helping Hand Social Care Ltd | Blyth | 2023 |
| A Hersi Consultancy Service Ltd | Derby | 2017 |
| A Hewson Ltd | Sandy | 2008 |
| A Hill Consultancy Ltd | Warrington | 2025 |
| A Hill Marketing Ltd | Aylesbury | 2026 |
| A Hiney-Bancroft Limited | Shenstone | 2013 |
| A Hirst Co-Ordinating Solutions Ltd | Sheffield | 2018 |
| A Hobbs Limited | Ilkley | 2018 |
| A Hobson Ltd | Malton | 2023 |
| A Holdar Consultancy Limited | Leicester | 2017 |
| A Holt Limited | London | 2016 |
| A Home in the Country Limited | Claypole, Newark | 2002 |
| A Hope Services Ltd | London | 2021 |
| A Hotel Designer Ltd | Newport | 2025 |
| A House to a Home - Drawing Solutions Ltd | Leicester | 2019 |
| A Howell Consulting Ltd | London | 2025 |
| A Hub Ltd | London | 2017 |
| A Hudson Engineering Ltd. | 5 West Victoria Dock Road | 2011 |
| A Hughes-Jones, Dyson & Co Ltd | Caernarfon | 2025 |
| A Human Business Limited | Gloucester | 2018 |
| A Hunter & Co Limited | Dorset | 2004 |
| A Hussain Enterprises Ltd | Birmingham | 2021 |
| A Hussein Psychology Ltd | London | 2026 |
| A I Closing Buddy Limited | Cambridge | 2026 |
| A I Immigration Services Ltd | Birmingham | 2024 |
| A I Innovations Studio Ltd | Chesham | 2025 |
| A I James & Co Limited | London | 2013 |
| A I P Construction Services Ltd | Market Drayton | 2020 |
| A I Recruitment Solutions Ltd | Carshalton | 2023 |
| A I Technology Solutions Ltd | Northolt | 2012 |
| A Ifezue Ltd | Altrincham | 2021 |
| A II Ltd | Motherwell | 2022 |
| A Ilascu Limited | Sheffield | 2018 |
| A Inact Ltd | London | 2025 |
| A Infinity a (AIA) Ltd | London | 2011 |
| A International Events Ltd | Glasgow | 2024 |
| A Intro Consultancy Limited | Reigate | 2010 |
| A Ioannides Ltd | Sale | 2024 |
| A Irvine Consulting Ltd | Wallington | 2022 |
| A IS for Architecture Limited | London | 2021 |
| A IS for Morenike Ltd | Bristol | 2021 |
| A Ives Consulting Ltd | Hull | 2026 |
| A J & Co. Consulting Ltd | Huntingdon | 2025 |
| A J & TM Bean Ltd | Spalding | 2010 |
| A J Access Holdings Limited | Normanton | 2011 |
| A J Accountancy and Financial Management Limited | Stourbridge | 2009 |