| Night and Night Ltd | Hospitality | 2022 |
| Night Mode Ltd | Manufacturing | 2019 |
| Night Nightz Limited | Real estate | 2019 |
| Nightingale Rally Media Ltd | Information & communication | 2023 |
| Nine Elephants Limited | Hospitality | 2017 |
| Nirrk Ltd | Wholesale & retail | 2022 |
| Nisa Dunvant Limited | Wholesale & retail | 2017 |
| Nisaba Ltd | Real estate | 2022 |
| Nishimura Limited | Hospitality | 2014 |
| Niss-Tec Limited | Wholesale & retail | 1999 |
| Niwdem Associates Ltd | Professional & scientific | 2024 |
| NIX Aesthetics Ltd | Other services | 2024 |
| Nixi Lounge Limited | Other services | 2024 |
| Nixihealth Group Limited | Wholesale & retail | 2023 |
| Nixon Delivers Ltd | Transport & logistics | 2025 |
| NJ Project Consultancy Limited | Water & waste | 2018 |
| NJ Restorations Limited | Wholesale & retail | 2016 |
| Nj&K Enterprise Ltd | Wholesale & retail | 2020 |
| NJD Couriers Wales Ltd | Transport & logistics | 2025 |
| NJD Logistics Ltd | Transport & logistics | 2022 |
| NJD Performance Limited | Other services | 2022 |
| Njdlogistics(Ammanford) Limited | Transport & logistics | 2023 |
| NJH Car Sales Limited | Wholesale & retail | 2026 |
| NJJ Coaching Ltd | Other services | 2020 |
| Njord Group Ltd | Financial services | 2023 |
| Njow Limited | Financial services | 2017 |
| NKD Accounting Services Ltd | Professional & scientific | 2025 |
| NKR Consultants Ltd | Transport & logistics | 2023 |
| NLJ Sound Limited | Information & communication | 2016 |
| NLP Rentals Ltd | Real estate | 2021 |
| NLW Building Ltd | Construction | 2025 |
| NMJ Property Holdings Limited | Real estate | 2018 |
| Nmultitrade Ltd | Construction | 2026 |
| Nnam Property Holdings Ltd | Hospitality | 2025 |
| NO 1 Bar & Distillery Limited | Hospitality | 2024 |
| NO 59 Skin and Beauty Ltd | Other services | 2018 |
| NO 7EVEN Ltd | Other services | 2019 |
| NO Crash Ltd | Wholesale & retail | 2023 |
| NO Gain Without Pain Ltd | Administrative & support | 2017 |
| NO Limit Construction Ltd | Construction | 2023 |
| NO. 11 Housing Limited | Real estate | 2024 |
| NO. 12 Kitchen Ltd | Hospitality | 2022 |
| NO. 18 Cafe Swansea Ltd | Hospitality | 2024 |
| NO. 26 Mumbles Ltd | Hospitality | 2024 |
| NO. 86 Estate Agency Ltd | Real estate | 2018 |
| NO.6 Lettings Ltd | Real estate | 2020 |
| NO.8 Project Ltd | Professional & scientific | 2019 |
| Noah Swansea Ltd | Hospitality | 2025 |
| Noah's ARK Childcare Limited | Education | 2004 |
| Noahs Yard Ltd | Hospitality | 2010 |
| Noble Green Property Ltd | Real estate | 2026 |
| Nobuhle Ltd | Health & social care | 2022 |
| Noel Consulting Ltd | Professional & scientific | 2026 |
| Nofela CIC | Wholesale & retail | 2025 |
| Nohania Design Ltd | Professional & scientific | 2019 |
| NOK NOK Authentic Thai Food Ltd | Hospitality | 2025 |
| Nomad Bar & Kitchen Ltd | Hospitality | 2026 |
| Nonna Assunta Ltd | Manufacturing | 2024 |
| Nonna's Deliciously Different Limited | Hospitality | 2021 |
| Nook Parcel Box Limited | Transport & logistics | 2026 |
| Nopm Swansea Ltd | Real estate | 2010 |
| Norfolk Building and Maintenance Limited | Construction | 2013 |
| Norfolk Street Hotel & Residence Limited | Real estate | 2017 |
| Norma Davies Opticians Limited | Health & social care | 2010 |
| North Quay (Pembroke) Management Company Limited | Real estate | 2005 |
| North Street Standard Limited | Hospitality | 2014 |
| Northeast Performance Ltd | Real estate | 2024 |
| Northedge Media Ltd | Information & communication | 2025 |
| Northern Curries Ltd | Hospitality | 2026 |
| Northrise Projects Limited | Real estate | 2025 |
| Northwave Solutions Ltd | Information & communication | 2026 |
| Nortia TS Ltd | Transport & logistics | 2024 |
| Norton Consultancy Ltd | Professional & scientific | 2025 |
| Norton Lamps Limited | Wholesale & retail | 1998 |
| Norwales Property Ltd | Real estate | 2021 |
| Norwegian Homes Limited | Construction | 2002 |
| Notla Ventures Limited | Education | 2025 |
| Nottage Mews Management Company Limited | Households | 1986 |
| Nottingham Accountancy Limited | Professional & scientific | 2021 |
| Nova Forma Designs Ltd | Information & communication | 2025 |
| Nova Onda Ceramics Ltd | Wholesale & retail | 2025 |
| Nova-Grace Engineering Ltd | Construction | 2024 |
| Novacp Ltd | Transport & logistics | 2025 |
| Novagrid Energy Limited | Energy | 2026 |
| Novaminster Limited | Real estate | 1990 |
| Novare Enterprises Ltd | Real estate | 1975 |
| Novasol Energy Ltd | Construction | 2025 |
| Novus Gower Limited | Education | 2022 |
| NOW OT Ltd | Health & social care | 2024 |
| NOX Media Limited | Professional & scientific | 2023 |
| Noxstella Ltd | Professional & scientific | 2022 |
| NR Milandu Ltd | Health & social care | 2020 |
| NRC Financial Services Limited | Financial services | 2020 |
| NRG Cleaning Services Limited | Administrative & support | 2006 |
| NRH Investments Limited | Real estate | 2017 |
| NRP Groundworks & Landscape Ltd | Administrative & support | 2019 |
| Nsasl Limited | Administrative & support | 2026 |
| Nsilver Limited | Health & social care | 2025 |
| NSP HR Solutions Limited | Administrative & support | 2017 |
| NT Fabrications Ltd | Manufacturing | 2024 |