| JAW Industries Ltd | Manufacturing | 2019 |
| Jiple Transport Ltd | Transport & logistics | 2021 |
| JJC Properties Limited | Wholesale & retail | 2012 |
| John Davies Carpentry Contractor Limited | Manufacturing | 2024 |
| JS Maintenance Masters Ltd | Construction | 2026 |
| JSE Contracts Ltd | Construction | 2022 |
| JT Support Therapy Ltd | Health & social care | 2024 |
| Jumpers for Goalposts Ltd | Information & communication | 2022 |
| K&A Property Construction Ltd | Construction | 2026 |
| K&N Nails Bar Ltd | Other services | 2025 |
| Kal’S Courier Ltd | Transport & logistics | 2025 |
| Kayde Care Ltd | Health & social care | 2025 |
| Kendall Roofing Ltd | Construction | 2015 |
| Kids With Bricks Ltd | Education | 2018 |
| Kindareel Limited | Administrative & support | 2025 |
| KMC Showroom Ltd | Wholesale & retail | 2020 |
| KOZ1 Barber Shop Ltd | Other services | 2025 |
| KP Commissioning Limited | Professional & scientific | 2010 |
| Krafty Cousins Ltd | Arts & recreation | 2024 |
| Ku-Kublessd Limited | Health & social care | 2015 |
| L N Property Maintenance Limited | Construction | 2024 |
| L W Engineering Services Limited | Administrative & support | 2005 |
| Lancaster Street 28/09/1967 Limited | Extraterritorial | 2014 |
| Laxminarayan Trading Ltd | Wholesale & retail | 2024 |
| LD Nails & Beauty Ltd | Other services | 2025 |
| Lejone Healthcare Services Limited | Health & social care | 2025 |
| Lema Electrical Ltd | Construction | 2021 |
| Lilly and Rose Florist Ltd | Wholesale & retail | 2024 |
| Limitless Kitchens Ltd | Manufacturing | 2019 |
| LJD Luxury Trading Ltd | Wholesale & retail | 2023 |
| Llanhilleth & District Bowls Club Limited | Arts & recreation | 2019 |
| Llanhilleth Miners Institute Limited | Education | 2007 |
| Lmach Ltd | Construction | 2018 |
| Lndn Properties Ltd | Real estate | 2024 |
| Lokannie Limited | Real estate | 2022 |
| Longway Express Ltd | Transport & logistics | 2024 |
| Lorraine Flower Limited | Administrative & support | 2025 |
| Lowcroft Limited | Information & communication | 2015 |
| Luke the Plumber Ltd | Construction | 2026 |
| Lupus Albus Ltd | Administrative & support | 2025 |
| LW Property Management Services Limited | Real estate | 2022 |
| Lydia Smith Limited | Health & social care | 2016 |
| M & J Property Developers Limited | Construction | 2013 |
| M B L Installations Limited | Manufacturing | 2024 |
| M J Builders (Abergavenny) Limited | Construction | 2016 |
| M W W Maintenance Limited | Construction | 2002 |
| M&Jk Properties Limited | Real estate | 2015 |
| MAA Tandoori Takeaway Ltd | Hospitality | 2025 |
| Macro Finance Systems Limited | Information & communication | 2005 |
| Management Solutions for Business Ltd | Professional & scientific | 2021 |
| Mark Wallace Electrical Limited | Construction | 2011 |
| Meats Meats MOW Ltd | Wholesale & retail | 2025 |
| Mehat SIX Bells Limited | Wholesale & retail | 2018 |
| MF Takeaway Ltd | Hospitality | 2024 |
| MFS Group Ltd | Construction | 2019 |
| MFS Surrey Ltd | Construction | 2024 |
| MG Heating Solutions Limited | Professional & scientific | 2011 |
| MI Little PAD Limited | Information & communication | 2014 |
| Mikes Unboxing Ltd | Information & communication | 2026 |
| Mini Me's Person Bach FEL FI Ltd | Education | 2014 |
| MK 16 Ltd | Wholesale & retail | 2026 |
| Mogfords Refurbs Limited | Manufacturing | 2016 |
| Motaquip Excel Factors Limited | Wholesale & retail | 2004 |
| Mother Natures Goodies Retail Ltd | Wholesale & retail | 2019 |
| Motoring Way Ltd | Wholesale & retail | 2023 |
| MTM ARB Ltd | Administrative & support | 2025 |
| Muddy Puddles Childcare Services Ltd | Health & social care | 2018 |
| MWC Aerotrim Limited | Manufacturing | 2016 |
| N & K Renovations Limited | Real estate | 2026 |
| N Joy Pizza Ltd | Hospitality | 2019 |
| N M Williams Services Ltd | Transport & logistics | 2024 |
| Nandawon Ltd | Information & communication | 2021 |
| Naturiol Interiors Ltd | Manufacturing | 2023 |
| Newport Convenience Stores Ltd | Administrative & support | 2017 |
| Newport Waterbeds Limited | Manufacturing | 2008 |
| Nicklin Property Developments Ltd | Real estate | 2025 |
| Noble Balti House Ltd | Hospitality | 2016 |
| NOT Just Travel BEV Newman Ltd | Administrative & support | 2022 |
| Nottage Store Ltd | Wholesale & retail | 2024 |
| NW Motor Trade Limited | Wholesale & retail | 2020 |
| Omkara Real Estate Ltd | Real estate | 2025 |
| Orange 5 Group Ltd | Other services | 2025 |
| ORL Consulting Limited | Professional & scientific | 2025 |
| Palm Studio - Recording & Rehearsal Ltd | Information & communication | 2019 |
| Parsons Executive Coaching Ltd | Professional & scientific | 2020 |
| Paul Raymond Grimstead Limited | Transport & logistics | 2013 |
| Pauline Paul Childcare Ltd | Health & social care | 2026 |
| Pearce & Sons Limited | Wholesale & retail | 2005 |
| Pemberton Revive Ltd | Real estate | 2026 |
| Peny-Bryn House Ltd | Health & social care | 2021 |
| Phoenix Domestic Abuse Services | Health & social care | 2017 |
| Phoenix Home Installations Limited | Construction | 2016 |
| Phoenix Plastering + Decorating Ltd | Construction | 2025 |
| Pile IT High Limited | Extraterritorial | 2014 |
| Pipeplan UK Ltd | Manufacturing | 2022 |
| Pointing Dog Property Limited | Extraterritorial | 2023 |
| Posidata Limited | Information & communication | 2015 |
| Positif Care Ltd | Health & social care | 2018 |
| Positif Education Limited | Education | 2026 |
| Positif Properties and Maintenance Limited | Households | 2024 |