| 365 Fire & Security Group Limited | Administrative & support | 2024 |
| 5 Stars Tasty Food Ltd | Hospitality | 2024 |
| A and H Path Ltd | Health & social care | 2020 |
| A Class Apart Limited | Wholesale & retail | 2014 |
| A D Asset Management Ltd | Financial services | 2018 |
| A Fairy Godmother Limited | Hospitality | 2018 |
| A J H Wealth Management Limited | Financial services | 2009 |
| A&J Renovation and Construction Limited | Construction | 2025 |
| A&N Media LLP | | 2020 |
| A&T Tiling Specialists Limited | Construction | 2025 |
| A2Z Hire Limited | Administrative & support | 2025 |
| AA Painting and Decorating Ltd | Construction | 2025 |
| Absolute Property Developers Limited | Construction | 2012 |
| AC Jones Services Limited | Other services | 2019 |
| Active Health Chiropractic Clinic Ltd | Health & social care | 2018 |
| Alarp Ltd | Real estate | 2015 |
| ARC Prime Lettings Ltd | Real estate | 2024 |
| Ardwyn Walk Management Company Limited | Real estate | 2015 |
| Argae House Equestrian Limited | Agriculture & fishing | 2000 |
| Armchair Lettings Ltd | Real estate | 2020 |
| Art Sparks Cardiff Ltd | Education | 2026 |
| Attica & Daughters Limited | Administrative & support | 2008 |
| B L Groundworks Services Limited | Administrative & support | 2017 |
| BA Cheshire Ltd | Construction | 2021 |
| Bannau Lodges Limited | Hospitality | 2025 |
| Barefoot Medicine Ltd | Health & social care | 2020 |
| Bashed Sauces UK Ltd | Manufacturing | 2021 |
| Bashed UK Ltd | Hospitality | 2020 |
| Bdjd Properties Ltd | Real estate | 2012 |
| Beevfry Estates Limited | Extraterritorial | 1945 |
| Beija Flor Ltd | Hospitality | 2025 |
| Benjamin Fail Ltd | Wholesale & retail | 2026 |
| Benjo Productions Ltd | Arts & recreation | 2023 |
| Bespoke Hair (Bridgend) Ltd | Other services | 2022 |
| Binas Barkin Beauties Limited | Agriculture & fishing | 2024 |
| Black Lobster Limited | Other services | 2023 |
| Blas Cyfryngau Cymru CBC | Arts & recreation | 2023 |
| BLP Trade Ltd | Wholesale & retail | 2017 |
| Bluesky Surveying Ltd | Construction | 2020 |
| Bluestone Corporation Ltd | Construction | 2016 |
| BNY Properties Ltd | Real estate | 2023 |
| Bobie's Limited | Health & social care | 2021 |
| Brandrocker Ltd | Professional & scientific | 2018 |
| Bridesbay Limited | Real estate | 2017 |
| Bright Rentals Limited | Real estate | 2026 |
| Brown Bear Games Limited | Wholesale & retail | 2022 |
| Brown Bear Homes Limited | Real estate | 2026 |
| Brusco Limited | Real estate | 2009 |
| BTW Productions Ltd | Arts & recreation | 2019 |
| Business Loan Services (UK) Ltd | Financial services | 2013 |
| Cabledd Ltd | Professional & scientific | 2019 |
| CAE SYR Dafydd Freehold Management Company (2008) Limited | Real estate | 2008 |
| Caffeine Creative Limited | Professional & scientific | 2013 |
| Calon People Ltd | Professional & scientific | 2023 |
| Cannan Consultancy Services Ltd | Financial services | 2022 |
| Cardboy Creative Limited | Professional & scientific | 2024 |
| Cardiff Scuba Limited | Wholesale & retail | 2005 |
| Cardiff Sports Medicine Services Limited | Health & social care | 2007 |
| Caredig Care Ltd | Health & social care | 2023 |
| Castle Wood Dinas Powys Ltd | Agriculture & fishing | 2024 |
| Cennedi Ltd | Wholesale & retail | 2023 |
| Charles Grace Limited | Professional & scientific | 2022 |
| Charlieann Consulting Limited | Information & communication | 2023 |
| Charlotte Rose Hairdressing Ltd | Other services | 2020 |
| Chislet Properties Limited | Real estate | 2006 |
| CJM Trading and Investment Ltd | Professional & scientific | 2021 |
| CJT Business Change Limited | Administrative & support | 2025 |
| Clare Doyle Occupational Health Limited | Health & social care | 2016 |
| Cleaver Solutions Limited | Professional & scientific | 2015 |
| Click Electrical Limited | Construction | 2025 |
| Cobberdogs in the Community C.I.C. | Agriculture & fishing | 2021 |
| Cokel Woods Limited | Agriculture & fishing | 2024 |
| Consultancy.Coop LLP | | 2010 |
| Cozzy Insulation Services Ltd | Construction | 2023 |
| Craft*Folk Limited | Administrative & support | 1997 |
| Croffta Consultancy Limited | Professional & scientific | 2019 |
| Crupron Construction Limited | Construction | 1982 |
| Curious Maths Ltd | Education | 2017 |
| Cutzone Barbershop Ltd | Other services | 2025 |
| Cwmni Ad/Lib Cymru CYF | Arts & recreation | 2021 |
| Cwrt YR Eglwys Management Company Limited | Households | 2018 |
| Cyber CSI & Analysis Ltd | Information & communication | 2023 |
| Cyhoeddwyr Cambria Cyfyngedig | Information & communication | 2011 |
| Cymraeg Glazing Services Limited | Construction | 2006 |
| D & S Dean Limited | Administrative & support | 2014 |
| Daisy Graze Ltd | Manufacturing | 2015 |
| Dapperdox Ltd | Information & communication | 2018 |
| Darthvark Ltd | Wholesale & retail | 2020 |
| Dashman Ltd | Extraterritorial | 2012 |
| David Kennaway Films Limited | Information & communication | 2025 |
| DB Management Limited | Professional & scientific | 2000 |
| DHD Industries Limited | Wholesale & retail | 2024 |
| Diabetes Professional Advice Ltd | Health & social care | 2013 |
| Dinas Indian Takeaway Ltd | Hospitality | 2019 |
| Dinas Kebab Ltd | Hospitality | 2024 |
| Dinas Powis Athletic Club (R.F.) Limited | Arts & recreation | 1923 |
| Dinas Powis Lawn Tennis Club Limited | Arts & recreation | 1952 |
| Dinas Powis RFC Limited | Arts & recreation | 2018 |
| Dinas Powys IT Limited | Information & communication | 2007 |
| DMT Productions Ltd | Arts & recreation | 2018 |