| A&S Plant Construction and Land Drainage Ltd | Construction | 2007 |
| Aberafon Limited | Hospitality | 2023 |
| ACOUSTIC1 Hire Ltd | Professional & scientific | 2022 |
| ACOUSTIC1 Holdings Limited | Hospitality | 2015 |
| ACOUSTIC1 Limited | Wholesale & retail | 2007 |
| Acstro Limited | Professional & scientific | 2008 |
| Acton Maintenance Ltd | Other services | 2025 |
| AD Fencing and Plant Ltd | Administrative & support | 2015 |
| AJD Accountants Limited | Professional & scientific | 2014 |
| Akaboo Holdings Ltd | Real estate | 2025 |
| AL Thomas Limited | Agriculture & fishing | 2017 |
| Aled Lewis A'I FAB Plumbing Heating & Renewables Limited | Construction | 2021 |
| Aled Llŷr CYF | Information & communication | 2017 |
| Aled Thomas Planning Design Limited | Professional & scientific | 2006 |
| Alun Davies Building Contractors Ltd | Construction | 2005 |
| AMD Welding Services Ltd | Manufacturing | 2018 |
| Amelia Properties 2022 Ltd | Real estate | 2022 |
| Amman Valley Training Limited | Education | 2000 |
| Amsto Limited | Real estate | 2003 |
| Andre Properties Limited | Real estate | 1983 |
| Andrew Holmes Funfairs Ltd | Arts & recreation | 2019 |
| Andrew Lacey LLP | | 2010 |
| Andrew Vaughan Davies Ltd | Construction | 2017 |
| Apricity London Ltd | Education | 2018 |
| Artisan Estates Ltd | Real estate | 2016 |
| Aspect Developments (Swansea) Limited | Construction | 2018 |
| Aspect Developments (Wales) Ltd | Construction | 2006 |
| Aspect Developments Carmarthen Ltd | Construction | 2017 |
| Aspect Developments Llandeilo Limited | Professional & scientific | 2015 |
| Axis Lease Management Limited | Financial services | 1998 |
| Baldwin Business Operations Ltd | Public administration | 2025 |
| Barmouth (N Wales) Accountancy Services Ltd | Professional & scientific | 2020 |
| Barr & Co Jewellery Ltd | Manufacturing | 2017 |
| BDW Servicing & Repairs Ltd | Wholesale & retail | 2018 |
| Beaton Thomas Scarlioli Limited | Professional & scientific | 1992 |
| Bedlam Properties Ltd | Real estate | 2019 |
| Beech Davies Jones Consulting Limited | Professional & scientific | 2006 |
| BJP Residential Limited | Real estate | 2009 |
| Black BEE Books Ltd | Information & communication | 2020 |
| Black Mountain Distillery Ltd | Manufacturing | 2022 |
| Black Mountain Fire Consultancy Ltd | Professional & scientific | 2024 |
| Black Mountain Fire Ltd | Construction | 2022 |
| Black Mountain Racing Ltd | Arts & recreation | 2026 |
| Bolt Electric Builders Ltd | Construction | 2025 |
| Box of Fists Llandeilo Boxing Gym Ltd | Arts & recreation | 2023 |
| Brian Ranns Trading Ltd | Transport & logistics | 2025 |
| BRJ Properties Limited | Real estate | 2024 |
| BRJ Property Development Limited | Real estate | 2024 |
| Brunswick Court Management (Gloucester) Limited | Real estate | 2013 |
| Brynteilo Management Company Limited | Real estate | 2007 |
| Bush House Limited | Extraterritorial | 2005 |
| C L James Limited | Agriculture & fishing | 2002 |
| Cactus Storage Ltd | Administrative & support | 2026 |
| Caeglas Residential Home Ltd | Health & social care | 2018 |
| Cambria Publishing Ltd | Other services | 2020 |
| Cambrian Psychology Ltd | Health & social care | 2018 |
| Cambrian Woodlands Limited | Agriculture & fishing | 1996 |
| Capel Celf Community Interest Company | Arts & recreation | 2025 |
| Carreg Land Limited | Agriculture & fishing | 2021 |
| Carreg Law Limited | Professional & scientific | 2014 |
| Cartrefi Clyd Cymru CYF | Real estate | 2016 |
| Cartrefi D & D Homes Ltd | Construction | 2020 |
| Cartrefi RENOV8 Homes Ltd | Real estate | 2022 |
| Castan Cabins Ltd | Manufacturing | 2022 |
| Cawdor Arms Ltd | Hospitality | 2016 |
| Cawdor Arms Property Ltd | Real estate | 2023 |
| Cawdor Estates Ltd | Real estate | 2016 |
| Cefncilwg Property Limited | Agriculture & fishing | 2020 |
| Cennen Homes Ltd | Construction | 2021 |
| Citrine Cosmetics Ltd | Wholesale & retail | 2021 |
| Citrine Skincare Ltd | Wholesale & retail | 2021 |
| CLO Carbon Cymru Ltd | Professional & scientific | 2021 |
| Clustog CYF | Manufacturing | 2025 |
| Clwb Peldroed Llandeilo AFC CYF | Arts & recreation | 2022 |
| Clwb Rygbi Y Tymbl CYF | Arts & recreation | 2015 |
| Clwyd-Powys Archaeological Trust(The) | Professional & scientific | 1975 |
| CMF Building & Landscaping Limited | Construction | 2023 |
| Cnbe Group Ltd | Financial services | 2023 |
| Colledge Associates Limited | Information & communication | 2014 |
| Cornerstone Close Ltd | Construction | 2022 |
| Corwellness Ltd | Health & social care | 2025 |
| Cosmic Earth Medicine Ltd | Other services | 2023 |
| Coward Properties Ltd | Real estate | 2021 |
| Crafts Alive Ltd | Wholesale & retail | 1995 |
| Creuddyn Bridge Residential Park Limited | Hospitality | 2022 |
| Crochan CWM Cothi C.I.C. | Wholesale & retail | 2019 |
| Crown Stores (Ffairfach) Ltd | Wholesale & retail | 2025 |
| Crown Stores (Llandeilo) Ltd | Wholesale & retail | 2013 |
| CWB Electrical Engineers Limited | Construction | 2012 |
| Cwmni DL Davies Trefnwyr Angladdau CYF | Other services | 2026 |
| Cwrt Henri Farms Ltd | Agriculture & fishing | 2009 |
| Cyfoes | Wholesale & retail | 2013 |
| Cymdeithas Bethlehem Dyffryn Ceidrych Association Limited | Arts & recreation | 2004 |
| Cymdeithas Pysgota Llandeilo Angling Association Cyfingedig | Arts & recreation | 2011 |
| D & R Davies Limited | Agriculture & fishing | 2020 |
| D Davies Plumbing and Heating Ltd | Construction | 2014 |
| D G Davies Ltd | Construction | 2015 |
| D M R (West Wales) Ltd | Wholesale & retail | 2002 |
| Dalar Davies Limited | Agriculture & fishing | 2020 |
| Dalar Properties Limited | Real estate | 2023 |