| 121SECURITYUK Ltd | Administrative & support | 2014 |
| 1ST Line Services Ltd | Professional & scientific | 2023 |
| 2006 Holdings Ltd | Professional & scientific | 2015 |
| 2006 Ltd | Construction | 2015 |
| 25 Wright Close Limited | Real estate | 2025 |
| 2LET Property Management Ltd | Households | 2023 |
| 2ND Hand Stealz Limited | Wholesale & retail | 2025 |
| 3 Series Spares Ltd | Wholesale & retail | 2011 |
| 32ND Street Ltd | Hospitality | 2025 |
| 3SS Convenience Store Ltd | Wholesale & retail | 2026 |
| 4 Colour Digital Limited | Manufacturing | 2013 |
| 49 Aperitif Limited | Wholesale & retail | 2019 |
| 7TH Heaven Limited | Extraterritorial | 2001 |
| 8 Ballers Limited | Arts & recreation | 2020 |
| A & S Commercial Repairs Limited | Wholesale & retail | 2003 |
| A & S Developments (Maesteg) Limited | Construction | 2008 |
| A Bull Groundworks Ltd | Construction | 2025 |
| A Ferrymans Tale Ltd | Hospitality | 2024 |
| A J Richards Services Limited | Manufacturing | 2023 |
| A Little Company About Lemons Limited | Information & communication | 2014 |
| A M Richards Services Limited | Professional & scientific | 2023 |
| A P Collins Haulage Limited | Transport & logistics | 2017 |
| A&S Storage Ltd | Transport & logistics | 2023 |
| A.R.M. Heritage Railway Services LES Ltd | Professional & scientific | 2024 |
| A1 Chippy Ltd | Hospitality | 2017 |
| A1 Timber Frame Limited | Construction | 2015 |
| A2B Active Sport CIC | Arts & recreation | 2013 |
| AA Rental Property Limited | Real estate | 2024 |
| AB Safety Associates Ltd | Administrative & support | 2023 |
| Abbey Childcare Ltd | Education | 2022 |
| Aber Parc Ltd | Transport & logistics | 2025 |
| Aberacon Limited | Other services | 2025 |
| Aberavon & Port Talbot Rugby Football Club Limited | Arts & recreation | 2001 |
| Aberavon Company Services Ltd | Professional & scientific | 2025 |
| Aberavon Green Stars Rugby Football Club Limited | Arts & recreation | 2019 |
| Aberavon Harlequins RFC Limited | Arts & recreation | 2012 |
| Aberavon Integrated Children's Centre | Education | 2004 |
| AC Appliances and Hire Limited | Real estate | 2000 |
| AC James Property Ltd | Real estate | 2025 |
| Academy Arts by Ebony & Jalisa Ltd | Arts & recreation | 2019 |
| ACADEMY4 Projects Group Ltd | Hospitality | 2022 |
| Acbookkeepingservices Limited | Professional & scientific | 2013 |
| Accountancy Solutions (GB) Limited | Professional & scientific | 2004 |
| ACCUR8 Building and Project Management Ltd | Construction | 2024 |
| Ace Car and Van Repairs Limited | Wholesale & retail | 2012 |
| Acheebo Chem Ltd | Wholesale & retail | 2005 |
| ACS GAS Training and Assessment Centre Ltd | Education | 2018 |
| ACS Industrial Cladding Limited | Construction | 2016 |
| ACS Safety Training and Consultancy Limited | Education | 2025 |
| Action Property Maintenance Ltd | Construction | 2011 |
| AD Industrial Cleaning Ltd | Administrative & support | 2025 |
| Adam Pizza Limited | Hospitality | 2008 |
| Adapt Group Limited | Construction | 2023 |
| Addiscott Arts Academy Ltd | Arts & recreation | 2024 |
| ADJ Plumbing & Property Services Limited | Construction | 2026 |
| Advanced Door Systems Ltd | Construction | 2025 |
| Advanced Info & Tech Solutions Ltd | Construction | 2022 |
| Adventure Togs Limited | Wholesale & retail | 2004 |
| AE 78 Ltd | Hospitality | 2025 |
| Aegis Fire Defence Ltd | Construction | 2026 |
| AER Assist Limited | Manufacturing | 2023 |
| Afan a Blast Ltd | Wholesale & retail | 2017 |
| Afan Aggregates & Building Supplies Ltd | Wholesale & retail | 2024 |
| Afan Ales & Fine Wines Ltd | Wholesale & retail | 2021 |
| Afan Bricklaying and Construction Services Ltd | Construction | 2024 |
| Afan Consultancy in Education (Ace) Ltd | Professional & scientific | 2026 |
| Afan Ecommerce Ltd | Arts & recreation | 2025 |
| Afan Group Ltd | Financial services | 2020 |
| Afan Homes Limited | Real estate | 2020 |
| Afan Landscapes Limited | Construction | 1979 |
| Afan Lido Football Club Limited | Arts & recreation | 2025 |
| Afan Rainforest Alliance CIC | Arts & recreation | 2025 |
| Afan Takeaway Ltd | Hospitality | 2025 |
| Afan Treescapes Limited | Construction | 2020 |
| Afan Tyre Discount Centre Limited | Wholesale & retail | 1978 |
| Afan United Football Club Ltd | Arts & recreation | 2022 |
| Afan Vale Ltd | Manufacturing | 2015 |
| Afan Valley Community Leisure | Arts & recreation | 2015 |
| Afan Valley Construction Ltd | Construction | 2025 |
| Afan Valley Melts Limited | Manufacturing | 2020 |
| Afan Valley Surveyors Ltd | Professional & scientific | 2024 |
| Affinity CRM Consultants Ltd | Information & communication | 2016 |
| AH Foods PVT Ltd | Hospitality | 2026 |
| Ailarian Ltd | Manufacturing | 2024 |
| AIM2SUSTAIN Properties Ltd | Real estate | 2013 |
| Air Assault UK Ltd | Arts & recreation | 2019 |
| Air Revolution Technologies UK Ltd | Manufacturing | 2020 |
| AJ Plant Hire (Wales) Ltd | Construction | 2021 |
| AJ Wilson Property Ltd | Real estate | 2024 |
| AJC Energy Limited | Energy | 2021 |
| AKC Plastering Ltd | Construction | 2026 |
| Akinci Ltd | Hospitality | 2019 |
| AKSHA3 Ltd | Wholesale & retail | 2026 |
| Al&M Properties Ltd | Real estate | 2025 |
| Al's Industrial Cleaners Limited | Administrative & support | 2002 |
| Alan Bushell Racing Ltd | Arts & recreation | 2018 |
| Alandar Ltd | Information & communication | 2019 |
| Albayrak Electrics Ltd | Construction | 2020 |
| Alcon Construction Ltd | Construction | 2025 |
| Aledrhysjones Ltd | Wholesale & retail | 2021 |