| 46 Denmark Villas Hove Limited | Real estate | 2007 |
| 46 Ninian Management Company Ltd | Real estate | 2025 |
| 47 - 76 Heol Staughton RTM Company Ltd | Households | 2022 |
| 47 BP Ltd | Other services | 2014 |
| 47 Conway Road Ltd | Households | 2019 |
| 47 Ferry Road RTM Company Ltd | Real estate | 2014 |
| 47 Lincoln Street Management Ltd | Households | 2018 |
| 48 Broad Green Avenue RTM Company Limited | Real estate | 2015 |
| 48 Carat Ltd | Health & social care | 2018 |
| 491 Cowbridge Road East (Cardiff) Management Company Limited | Households | 2020 |
| 4CELL Electrical Ltd | Construction | 2013 |
| 4CVOICES Ltd | Arts & recreation | 2019 |
| 4D Property Company Limited | Real estate | 2015 |
| 4D Quantity Surveying Ltd | Professional & scientific | 2025 |
| 4D Soft Limited | Information & communication | 2021 |
| 4FREEDOM Ltd | Information & communication | 2025 |
| 4FUTURE Accountancy Ltd | Professional & scientific | 2023 |
| 4G Business Consultant Ltd | Energy | 2016 |
| 4G Developments 26 Ltd | Construction | 2026 |
| 4HANDS Services Limited | Construction | 2021 |
| 4KD Media Ltd | Information & communication | 2017 |
| 4LT Ltd | Administrative & support | 2012 |
| 4M Cloud Solutions Limited | Information & communication | 2026 |
| 4NE Limited | Construction | 2016 |
| 4NORI Ltd | Wholesale & retail | 2023 |
| 4PF Malloks Ltd | Hospitality | 2025 |
| 4PI Productions UK Limited | Arts & recreation | 2013 |
| 4PROPERTYUK Limited | Construction | 2013 |
| 4SITE Construction & Refurbishment Ltd. | Construction | 2017 |
| 4SQUARE Music Group Ltd | Information & communication | 2016 |
| 4TH Street Limited | Information & communication | 2015 |
| 4TRADING Limited | Wholesale & retail | 2017 |
| 4U2SMILE Ltd | Health & social care | 2024 |
| 4WALLS4RENT Ltd | Real estate | 2019 |
| 4WHEELSUK Ltd | Administrative & support | 2020 |
| 5 - 8 Petherton Mews RTM Company Limited | Households | 2024 |
| 5 Acts Films Ltd | Information & communication | 2024 |
| 5 Cyril Crescent Management Limited | Professional & scientific | 2006 |
| 5 Solutions Ltd | Wholesale & retail | 2018 |
| 5 Star Bricklaying Limited | Construction | 2017 |
| 5 Star CAB Ltd | Transport & logistics | 2025 |
| 5 Wholesale Ltd | Wholesale & retail | 2020 |
| 50 Marlborough Road Management Ltd | Real estate | 2022 |
| 50-56 Heath Halt Road Management Company Limited | Households | 2013 |
| 50/50A Sandringham Road Ltd | Real estate | 2018 |
| 51 Dominance Capital Limited | Professional & scientific | 2021 |
| 51 Property UK Ltd | Real estate | 2019 |
| 515 Events Ltd | Hospitality | 2017 |
| 515 Home Improvements Ltd | Construction | 2016 |
| 52 Cathedral Road (Cardiff) Residents Association Limited | Households | 1991 |
| 5343 Holdings Ltd | Administrative & support | 2012 |
| 54 Carlisle Street Management Limited | Households | 2019 |
| 54 Leckwith Road Ltd | Households | 2020 |
| 54 Penarth Road Management Ltd | Administrative & support | 2016 |
| 55 Investments Limited | Real estate | 2016 |
| 55 Penylan Road Ltd | Real estate | 2010 |
| 564 Cowbridge Road East Limited | Real estate | 2013 |
| 5678 Lynton Court Cardiff RTM Company Ltd | Real estate | 2020 |
| 57 Emerald Street Ltd | Real estate | 2023 |
| 57 Penylan Road Management Ltd | Real estate | 2022 |
| 57 Stacey Road Management Company Limited | Professional & scientific | 2003 |
| 57 Taxis Limited | Transport & logistics | 2005 |
| 5A-6B Uppercliff Close Limited | Households | 2019 |
| 5BRAND Advertising Agency Ltd | Professional & scientific | 2022 |
| 5CEEZ Ltd | Information & communication | 2025 |
| 5CG Consultancy Ltd | Professional & scientific | 2026 |
| 5DB Ltd | Construction | 2017 |
| 5DP Group Ltd | Education | 2020 |
| 5G Analyst Ltd | Wholesale & retail | 2019 |
| 5HEROS | Professional & scientific | 2025 |
| 5K2PB Limited | Arts & recreation | 2019 |
| 5KITCHEN Ltd | Hospitality | 2025 |
| 5M Lines Ltd | Wholesale & retail | 2025 |
| 5NH Trading Limited | Hospitality | 2019 |
| 5SJ Limited | Information & communication | 2024 |
| 5X Ltd | Financial services | 2021 |
| 6 Arlington Villas Management Company Limited | Households | 2003 |
| 6 Claude Road Management Company Limited | Real estate | 2010 |
| 6 Connaught Road Ltd | Households | 2018 |
| 6 Duffryn Close Limited | Extraterritorial | 2010 |
| 60 Newport Road Limited | Hospitality | 2023 |
| 60 Severn Grove Ltd | Households | 2018 |
| 6002 Ltd | Hospitality | 2019 |
| 62 Claude Road Right to Manage Company Ltd | Households | 2026 |
| 63-66 Heathmead RTM Company Limited | Households | 2024 |
| 64 Science Parks LLP | | 2025 |
| 65 COL Ltd | Real estate | 2025 |
| 65 Colum Road Residents Limited | Real estate | 2000 |
| 65 New Cavendish Street Management Limited | Professional & scientific | 2014 |
| 66 Expeditions Cruises (UK) Company Limited | Administrative & support | 2022 |
| 67 Cathedral Road Management Company Limited | Real estate | 2021 |
| 67 Penylan Road Limited | Real estate | 2002 |
| 67-69 Rhydypenau Road Management Company Limited | Real estate | 2000 |
| 68 Holdings Ltd | Real estate | 2023 |
| 69 and 69A Llandennis Road Management Limited | Real estate | 2008 |
| 6:59 Ltd | Construction | 2016 |
| 6CVENTURES Ltd | Financial services | 2020 |
| 6FORTS Limited | Health & social care | 2024 |
| 6IXT9 Ltd | Wholesale & retail | 2016 |
| 7 7 8 Limited | Wholesale & retail | 2003 |