| 2RM Studio LLP | | 2021 |
| 3 Circles Care Limited | Administrative & support | 2018 |
| 360 Design & Build Ltd | Construction | 2018 |
| 4SIDE Solutions Limited | Wholesale & retail | 2019 |
| 5 Sackville Gardens Management Limited | Real estate | 1994 |
| 56 Aslett Street Limited | Extraterritorial | 2001 |
| 57A & B Vere Street Management Company Limited | Households | 2005 |
| 70 Cumnor Hill Management Company Limited | Households | 2021 |
| 78 Angus Street Limited | Real estate | 2014 |
| A & H Property Management Limited | Real estate | 2017 |
| A Beaumont Holdings Ltd | Real estate | 2026 |
| A Bull Associates Ltd | Extraterritorial | 2016 |
| A Child's Boutique Limited | Wholesale & retail | 2013 |
| A G Minerals Limited | Mining & quarrying | 2012 |
| A J (Holdings) Limited | Financial services | 2014 |
| A J Couplings Limited | Administrative & support | 2008 |
| A.W.Bland & Sons,Limited | Real estate | 1910 |
| A.W.T. Developments Limited | Construction | 2004 |
| A1 Treatments Limited | Professional & scientific | 2015 |
| AB Plumbing and Property Services Ltd | Construction | 2025 |
| Abatam Ltd | Hospitality | 2019 |
| Abbey Equine Clinic Limited | Professional & scientific | 2019 |
| Abergavenny & Newport Market Auctioneers Ltd | Other services | 1988 |
| Abergavenny Agricultural Supplies Limited | Wholesale & retail | 1975 |
| Abergavenny Area Community Orchards and Gardens CIC | Agriculture & fishing | 2011 |
| Abergavenny Boxes Ltd | Manufacturing | 2019 |
| Abergavenny Brake and Clutch LP | | 1993 |
| Abergavenny Cricket Ground Company,Limited(The) | Arts & recreation | 1946 |
| Abergavenny Electrics Limited | Construction | 2011 |
| Abergavenny Fine Foods Limited | Manufacturing | 1987 |
| Abergavenny Food and Wines Ltd | Manufacturing | 2022 |
| Abergavenny Food Festival | Hospitality | 2001 |
| Abergavenny Fuels Limited | Wholesale & retail | 1979 |
| Abergavenny Garden Centre Ltd | Wholesale & retail | 2012 |
| Abergavenny Masonic Buildings Company.Limited(The) | Other services | 1905 |
| Abergavenny Masonic Centre Ltd | Other services | 2015 |
| Abergavenny MOT Centre Limited | Wholesale & retail | 2006 |
| Abergavenny Nursery Ltd | Education | 2022 |
| Abergavenny Nursery TOO Limited | Education | 2026 |
| Abergavenny Properties LLP | | 2020 |
| Abergavenny Property Management Limited | Households | 1989 |
| Abergavenny Restaurants Limited | Hospitality | 2013 |
| Abergavenny RFC Limited | Arts & recreation | 2017 |
| Abergavenny Strength and Conditioning C.I.C. | Arts & recreation | 2020 |
| Abergavenny Trading Company Limited | Hospitality | 2013 |
| Abergavenny Vineyards Ltd | Agriculture & fishing | 2022 |
| Abergavenny Writing Festival Community Interest Company | Arts & recreation | 2017 |
| Accelerate Sales Collective Ltd | Administrative & support | 2026 |
| Accendo Accountants Limited | Professional & scientific | 2012 |
| Access Marketing Ltd | Professional & scientific | 2022 |
| Accessibility Enterprise Ltd | Professional & scientific | 2021 |
| Acorn Studios Limited | Arts & recreation | 2023 |
| Acreleaf LLP | | 2021 |
| Active Financial Advisers Ltd | Financial services | 2019 |
| AD Property Venture Ltd | Real estate | 2024 |
| Adam Knock Agricultural Contracting Ltd | Agriculture & fishing | 2022 |
| Addingfield Limited | Real estate | 1965 |
| Addis & Whiteman Limited | Real estate | 2020 |
| ADH Motors Ltd | Wholesale & retail | 2021 |
| Adiuvare Solutions Ltd | Professional & scientific | 2021 |
| Advanced Formwork Solutions Ltd | Professional & scientific | 2025 |
| AEP Construction Ltd | Construction | 2018 |
| Aerial Focus Limited | Information & communication | 2015 |
| Aeromotive Design and Engineering Ltd. | Professional & scientific | 2015 |
| Affinity Searches Ltd | Professional & scientific | 2008 |
| Aftt Consultancy Ltd | Professional & scientific | 2025 |
| Agentic Ventures Limited | Financial services | 2025 |
| Agility Recruitment Solutions Limited | Administrative & support | 2012 |
| Aicr Health and Safety Limited | Administrative & support | 2009 |
| Aiphos Limited | Professional & scientific | 2026 |
| AJ Carmichael Limited | Information & communication | 2016 |
| AJB Building Consortium Ltd | Construction | 2025 |
| Akachut Consulting Limited | Administrative & support | 2024 |
| Alfowen Limited | Real estate | 2023 |
| ALL Saints DC Limited | Health & social care | 2018 |
| Allskin Laser Clinic Limited | Other services | 2026 |
| Alpha Canvassing Services Ltd | Administrative & support | 2024 |
| Alpha Plastics Solutions Ltd | Wholesale & retail | 2023 |
| Alphafence Ltd | Professional & scientific | 2008 |
| Altripan UK Limited | Agriculture & fishing | 2007 |
| Alun Griffiths (Contractors) Limited | Construction | 1980 |
| AM Auto Repairs Ltd | Wholesale & retail | 2022 |
| Amatsu Clinic Ltd | Health & social care | 2025 |
| Amsi Bros Limited | Hospitality | 2023 |
| Ancient Oak Consulting Limited | Administrative & support | 2011 |
| Andersons Accountancy Services Ltd | Professional & scientific | 2012 |
| Andrew Weed Ltd | Wholesale & retail | 2002 |
| Andy Howells Bulk Haulage Limited | Transport & logistics | 2003 |
| Angel T.V. Limited | Information & communication | 2001 |
| Angelica Films Ltd | Information & communication | 2022 |
| Annette's Cafe Diner Limited | Hospitality | 2003 |
| ANT Wallace Tree Services Ltd | Administrative & support | 2020 |
| Anthony Chaloner Golf Ltd | Wholesale & retail | 2023 |
| Anthony Jellard Associates LLP | | 2011 |
| Anti-Friction Components Limited | Wholesale & retail | 1976 |
| APB Real Estate Ltd | Real estate | 2024 |
| Apple County Cider Co Limited | Manufacturing | 2009 |
| Appletree Inn Developments Ltd | Construction | 2019 |
| Aquilla Lewis Ltd | Real estate | 2020 |
| Archer Dykstra Associates Ltd | Administrative & support | 2012 |