| MLS Retail (Porthcawl) Limited | Wholesale & retail | 2017 |
| Mmashamm Ltd | Real estate | 2022 |
| MMC 64 Ltd | Manufacturing | 2025 |
| MO500 Ltd | Other services | 2025 |
| Mobile One (Wales) Limited | Wholesale & retail | 1998 |
| Mobility Tools Limited | Manufacturing | 2013 |
| Modern Energy and Electrical Services Ltd | Construction | 2014 |
| Modern Motion Ltd | Wholesale & retail | 2020 |
| Money Value Accounting Ltd | Professional & scientific | 2017 |
| Monington Aviation Limited | Manufacturing | 2017 |
| Monster Swims Limited | Arts & recreation | 2026 |
| Moto-Lec (Wales) Ltd | Wholesale & retail | 2011 |
| Mountain Bull Ltd | Information & communication | 2024 |
| Mpaul Welding Ltd | Construction | 2023 |
| MPI Ford Limited | Financial services | 2011 |
| MR MC Turkish Barber Ltd | Other services | 2023 |
| MR. P'S Technology Limited | Manufacturing | 2014 |
| MT Lloyd Electrical Contractors Limited | Construction | 2018 |
| Multiparts (Properties) Limited | Real estate | 1979 |
| Munroshomedelivery Ltd | Transport & logistics | 2020 |
| Mustoe Project Services Ltd | Construction | 2020 |
| MW ETE Limited | Manufacturing | 2025 |
| MWM Maintenance Ltd | Professional & scientific | 2025 |
| Mymadhead Ltd | Wholesale & retail | 2025 |
| Myrtle Project Management Limited | Real estate | 2016 |
| MÔR Health Group Ltd | Health & social care | 2025 |
| MÔR Mortgages Limited | Financial services | 2023 |
| N&C Properties Ltd | Real estate | 2018 |
| Nash Accommodation Ltd | Real estate | 2023 |
| Nash Property Finance Ltd | Financial services | 2023 |
| Naughton Installation Limited | Construction | 2014 |
| NB Works Ltd | Construction | 2025 |
| Neil Morgan Creative Services Ltd | Professional & scientific | 2019 |
| Neurocollective Community Interest Company | Health & social care | 2023 |
| New Generation Developments Ltd | Construction | 2017 |
| Newport Asbestos Services Limited | Professional & scientific | 2020 |
| NGZ Consulting Ltd | Professional & scientific | 2020 |
| Nick Ager Haulage Limited | Transport & logistics | 2013 |
| Nigel Thomas Property Ltd | Real estate | 2021 |
| NME Engineering Limited | Professional & scientific | 2024 |
| Norbertradcliffe Ltd | Administrative & support | 2017 |
| Northern Crust Ltd | Hospitality | 2025 |
| Northern Star Distribution Ltd | Wholesale & retail | 2017 |
| Nottage Farms Limited | Agriculture & fishing | 1995 |
| Nottagecare Ltd | Public administration | 2022 |
| Nova Environmental Ltd | Professional & scientific | 2024 |
| Nrohmot Forever Ltd | Wholesale & retail | 2025 |
| Numerical Control Computer Sciences Limited | Information & communication | 2003 |
| Nutech Ltd | Construction | 2004 |
| NV Consult Limited | Professional & scientific | 2021 |
| O R Pearson Ltd | Health & social care | 2019 |
| Ocean Quest Limited | Arts & recreation | 2001 |
| Ogmore Court Residents Limited | Households | 2005 |
| Ollytechnic Limited | Manufacturing | 2022 |
| Omnivia Apps Ltd. | Wholesale & retail | 2025 |
| ON IT Group Holdings Ltd | Real estate | 2025 |
| ON IT Sports Ltd | Wholesale & retail | 2011 |
| Ontrack Education Solutions Limited | Education | 2010 |
| Opulenta Consulting Limited | Professional & scientific | 2014 |
| Owain Green Electrical Services Ltd | Construction | 2015 |
| Owen Carpentry Limited | Construction | 2006 |
| Oxygen Fitness Cornelly Limited | Arts & recreation | 2023 |
| P J Mullarkey Refractory Inspections & Supervision Ltd | Administrative & support | 2023 |
| P James Engineering Services Ltd | Manufacturing | 2026 |
| P&N Engineering Design Limited | Manufacturing | 2018 |
| Panda Bridge 2020 Limited | Hospitality | 2020 |
| Parc Store Ltd | Wholesale & retail | 2017 |
| Partaccom Limited | Professional & scientific | 2009 |
| Pathfinder Innovation Limited | Professional & scientific | 2025 |
| Paul Thomas Engineering Limited | Construction | 2007 |
| PBG Aero Ltd | Professional & scientific | 2019 |
| PC Schmidt Limited | Professional & scientific | 2018 |
| PCK Food Ltd | Hospitality | 2023 |
| Pegasus Heli Services (UK) Ltd | Manufacturing | 2008 |
| Penarth Limited | Financial services | 2019 |
| Petes Business Ltd | Manufacturing | 2014 |
| Philadelphia Villa Management Company Limited | Households | 2018 |
| Phorem Engineering Limited | Professional & scientific | 2024 |
| Pike Property Ltd | Real estate | 2013 |
| Pink Pants Consultancy Ltd | Professional & scientific | 2025 |
| PLM Aviation Limited | Transport & logistics | 2013 |
| PM Compositech Limited | Manufacturing | 2015 |
| Porthcawl Butchers Limited | Manufacturing | 2015 |
| Porthcawl Convenience Ltd | Wholesale & retail | 2025 |
| Porthcawl Funeral Services Limited | Other services | 2012 |
| Porthcawl GAS Services Limited | Administrative & support | 2012 |
| Porthcawl Insurance Consultants (UK) Limited | Financial services | 2001 |
| Porthcawl Landscaping Limited | Administrative & support | 2025 |
| Porthcawl Masonic Hall Company Limited | Construction | 1968 |
| Porthcawl Nails Limited | Other services | 2021 |
| Porthcawl Nutrition Limited | Administrative & support | 2024 |
| Porthcawl Padel Ltd | Arts & recreation | 2025 |
| Porthcawl Support Services Limited | Health & social care | 2000 |
| Porthcawl Towing Limited | Transport & logistics | 2018 |
| Porthcawl Town AFC Limited | Arts & recreation | 2024 |
| Porthcawl Windows Limited | Construction | 2020 |
| Porthcawl Young Men's Christian Association | Health & social care | 2012 |
| Portway Financial Limited | Professional & scientific | 2023 |
| Portway Porthcawl Limited | Other services | 2023 |
| Positive Lifestyles (Porthcawl) Limited | Health & social care | 2003 |