| 1 Laura Place Ltd | Real estate | 2019 |
| 1 Stop Lettings (Aber) Limited | Real estate | 2011 |
| 10A Corporation Street Ltd | Households | 2016 |
| 2 South Marine Terrace Limited | Households | 2015 |
| 20 Marine Terrace RTM Company Ltd | Households | 2026 |
| 27 Portland Street Ltd | Real estate | 2020 |
| 2SCONSULT Limited | Administrative & support | 2020 |
| 35 Portland Street Limited | Administrative & support | 2017 |
| 36 Shon Ltd | Financial services | 2025 |
| 3T'S Property Investment Limited | Real estate | 2025 |
| 4 Nevern Square Limited | Households | 1994 |
| 40 Portland Road Management Limited | Households | 2023 |
| 41 Portland ST Property Management Ltd | Households | 2016 |
| 44 Terrace Road Limited | Real estate | 2024 |
| 7 Maes Lowri Limited | Households | 2020 |
| 700C ASW Ltd | Manufacturing | 2025 |
| 820317 Ltd | Real estate | 2026 |
| 86 Finsbury Park Road Limited | Households | 2003 |
| 9 Laura Place Ltd | Extraterritorial | 2020 |
| A & LS Properties Ltd | Real estate | 2021 |
| A a International Ltd | Professional & scientific | 2005 |
| A and D Tyres Ltd. | Wholesale & retail | 2010 |
| A H Properties (Aberystwyth) Limited | Real estate | 2011 |
| A J Price Carpenter and Builder Ltd | Construction | 2022 |
| A P Cleaning & Service Ltd | Administrative & support | 2019 |
| A P Sourcing Limited | Wholesale & retail | 2011 |
| A S L Evans Limited | Administrative & support | 2012 |
| A Slice of Lime Limited | Wholesale & retail | 2014 |
| A.J. Leisure Limited | | 1980 |
| A1 Property Letting (UK) Limited | Real estate | 2013 |
| A1 Property Maintenance (Wales) Ltd | Other services | 2010 |
| Aabe Creative Limited | Wholesale & retail | 2015 |
| Aavishkar Limited | Health & social care | 2004 |
| ABA Property Management Limited | Real estate | 1997 |
| Abba Loos Limited | Administrative & support | 2007 |
| Abba Tree Specialist Ltd | Agriculture & fishing | 2018 |
| Aber Adventures Ltd | Arts & recreation | 2020 |
| Aber Armoury Ltd | Wholesale & retail | 2023 |
| Aber Business Consultancy Ltd | Professional & scientific | 2012 |
| Aber Commercial Trading Limited | Hospitality | 2022 |
| Aber Developments Limited | Construction | 2002 |
| Aber Food Surplus Ltd | Administrative & support | 2017 |
| Aber Glaziers Limited | Construction | 2019 |
| Aber Group Limited | Manufacturing | 2023 |
| Aber Heating Engineer's Ltd | Construction | 2012 |
| Aber Hotel Services Limited | Hospitality | 2026 |
| Aber Instruments Limited | Manufacturing | 1988 |
| Aber Sevens Ltd | Other services | 2026 |
| Aber Stoves & Flues Limited | Construction | 2011 |
| Aber Technologies Limited | Wholesale & retail | 2023 |
| Aber Ventures Ltd | Other services | 2024 |
| Aberforge Ltd | Professional & scientific | 2025 |
| Aberlab | Other services | 2015 |
| Aberystwyth & District Motorcycle Club | Arts & recreation | 2008 |
| Aberystwyth and District Hospice at Home Volunteers | Health & social care | 2014 |
| Aberystwyth Angling Association Limited(The) | Agriculture & fishing | 1929 |
| Aberystwyth Animal Health Laboratory Ltd | Professional & scientific | 2014 |
| Aberystwyth Car & Commercial Ltd | Wholesale & retail | 2025 |
| Aberystwyth Chiropody Centre Ltd | Wholesale & retail | 2012 |
| Aberystwyth Coffee Company Ltd | Wholesale & retail | 2021 |
| Aberystwyth Developments Limited | Hospitality | 2016 |
| Aberystwyth Glaziers Ltd | Construction | 2016 |
| Aberystwyth Gymnastics Club Ltd | Administrative & support | 2016 |
| Aberystwyth Heat & Power Ltd | Water & waste | 2017 |
| Aberystwyth Holiday Village Limited | Hospitality | 2017 |
| Aberystwyth Innovation and Enterprise Campus Limited | Agriculture & fishing | 2014 |
| Aberystwyth Liberal Association Limited | Hospitality | 2005 |
| Aberystwyth Management Company Ltd | Professional & scientific | 2007 |
| Aberystwyth Motorsports Limited | Administrative & support | 2021 |
| Aberystwyth Musicfest Ltd | Arts & recreation | 2016 |
| Aberystwyth Park Lodge Ltd | Hospitality | 1997 |
| Aberystwyth Pizza Ltd | Hospitality | 2025 |
| Aberystwyth Printmakers Ltd | Manufacturing | 2014 |
| Aberystwyth Rugby Football Club (2019) Limited | Arts & recreation | 2019 |
| Academy Disco Limited | Hospitality | 2024 |
| ADE & Anna Ltd | Hospitality | 2025 |
| Advancing Aberystwyth AR Y Blaen Ltd | Other services | 2016 |
| AE Lloyd & SON Limited | Wholesale & retail | 2014 |
| Ael-Y-Don and Gwen-Y-Don (Aberystwyth) Management Limited | Households | 1987 |
| Aerobicactions Ltd | Wholesale & retail | 2025 |
| Afan Construction Limited | Construction | 1988 |
| Afan Construction Services Limited | Real estate | 1996 |
| Afan Electrical Limited | Construction | 2002 |
| Afanfryn Leisure Ltd | Hospitality | 2023 |
| AG Accounting & Bookkeeping Ltd. | Professional & scientific | 2017 |
| Agent in a Box Ltd | Information & communication | 2026 |
| Agri Compliance Consultants Limited | Other services | 2022 |
| Agrifood Consulting Limited | Professional & scientific | 2024 |
| Agritrend Ltd | Wholesale & retail | 2013 |
| Ahava Limited | Wholesale & retail | 2026 |
| AHE Refrigeration & Electrical Ltd | Construction | 2013 |
| Aimmia Group Ltd | Wholesale & retail | 2025 |
| AJF (Aberystwyth) Limited | Professional & scientific | 2017 |
| AL Fencing Group Ltd | Construction | 2025 |
| AL Groundworks Limited | Construction | 2023 |
| Alaw Property Limited | Real estate | 2023 |
| Aled Ellis & Company Limited | Real estate | 1996 |
| Aled Ellis Sales Limited | Wholesale & retail | 2006 |
| Alegado Enterprise Ltd | Real estate | 2020 |
| ALH Properties Limited | Real estate | 2017 |