| Neverland Limited | Arts & recreation | 1989 |
| New Homes Yorkshire Ltd | Construction | 2024 |
| New Look Barbers Castleford Ltd | Administrative & support | 2025 |
| New Marmaris Ltd | Hospitality | 2024 |
| New Moon Nurseries Limited | Health & social care | 2009 |
| Newton Holdings Yorkshire Limited | Financial services | 2019 |
| Nexgen Investors Limited | Real estate | 2025 |
| Next Stop Store Ltd | Wholesale & retail | 2025 |
| NGF Group Ltd | Manufacturing | 2016 |
| Ngwazi Care Ltd | Health & social care | 2023 |
| NI Estates Ltd | Real estate | 2025 |
| Niagara Consulting Ltd | Administrative & support | 2014 |
| Nice Employer Limited | Administrative & support | 2014 |
| Nick Craig and Sons Ltd | Transport & logistics | 2018 |
| Nimbco Limited | Manufacturing | 2023 |
| Nimbus Building Products Limited | Professional & scientific | 2003 |
| Nissi Foods Ltd | Manufacturing | 2011 |
| Niwas Care Home Limited | Health & social care | 2021 |
| Nixon Allen Limited | Administrative & support | 2007 |
| NJ Sales Ltd | Wholesale & retail | 2025 |
| Nlwest Ltd | Real estate | 2025 |
| Nmph Limited | Construction | 2013 |
| Noble Homes (Yorkshire) Ltd | Extraterritorial | 2016 |
| Nolan Packaging Services Ltd | Administrative & support | 2018 |
| Norfolk Energy Partnerships Limited | Professional & scientific | 2020 |
| Normglad Ltd | Real estate | 2025 |
| North Fungi Ltd | Manufacturing | 2024 |
| North Notts Consultancy Ltd | Extraterritorial | 2024 |
| North Notts Properties Ltd | Construction | 2024 |
| Northamptonshire Energy Partnerships Limited | Professional & scientific | 2020 |
| Northern Ambition Academies Trust | Education | 2011 |
| Northern Automotive Limited | Wholesale & retail | 2020 |
| Northern Mens and Boyswear Limited | Manufacturing | 1992 |
| Northhill Care Homes Limited | Health & social care | 2003 |
| Northhill Residential Care Home - South Yorkshire Ltd | Health & social care | 2019 |
| Northsite Services Ltd | Construction | 2022 |
| Norton Healthcare Limited | Manufacturing | 1969 |
| Notorious Sales Ltd | Wholesale & retail | 2024 |
| Nottinghamshire Energy Partnerships Limited | Professional & scientific | 2020 |
| NOW Natural Organic Wellbeing Limited | Professional & scientific | 2021 |
| NSD Joinery Limited | Construction | 2024 |
| NSS Cleaning Limited | Administrative & support | 2009 |
| NSS Hire Limited | Administrative & support | 2003 |
| NSS Maintenance Limited | Administrative & support | 2005 |
| NSS Testing Limited | Construction | 2003 |
| Nsumpi-Boum Medi Care Limited | Health & social care | 2015 |
| Nsumpi-Boum Properties Limited | Real estate | 2024 |
| NUT Wood Cheesemongers Ltd | Hospitality | 2011 |
| Nutrition Supermarket Ltd | Professional & scientific | 2015 |
| NXT Level Estates Limited | Real estate | 2024 |
| Oak Electrical Limited | Construction | 1995 |
| Oak Interiors Ltd | Construction | 2004 |
| Oak Refrigeration and Mechanical Services Limited | Construction | 2002 |
| Oak Refrigeration Holdings Ltd | Construction | 2024 |
| Oaklands Residential Care Home - Leeds Ltd | Health & social care | 2014 |
| Oakwood Realty Ltd | Real estate | 2024 |
| Oceana Services Limited | Administrative & support | 2004 |
| Oceanic Inspection Limited | Construction | 2012 |
| Octant Technology Limited | Information & communication | 2026 |
| ODD Key Estates Limited | Real estate | 2026 |
| Okello Limited | Hospitality | 2026 |
| Olive Branches Ltd | Hospitality | 2024 |
| Oliver Sharp Catering Limited | Hospitality | 2015 |
| Oliwiertrans Ltd. | Transport & logistics | 2016 |
| OLN Play Limited | Construction | 2026 |
| Omco UK Limited | Manufacturing | 1995 |
| ON the Lash @ Hair "N" Beauty Ltd | Other services | 2015 |
| One Curry Limited | Hospitality | 2025 |
| One Empire Management Ltd | Arts & recreation | 2020 |
| One FEE Limited | Real estate | 2021 |
| One Night Ltd | Professional & scientific | 2024 |
| One Stop Safety Training Solutions Limited | Education | 2020 |
| Onlyflats Ltd | Real estate | 2023 |
| Opcm Ltd | Manufacturing | 2022 |
| Open Arms Living Ltd | Real estate | 2025 |
| Openteknologies Ltd | Wholesale & retail | 2023 |
| Optic Fibre Networks U.K. Ltd | Manufacturing | 2023 |
| Orcas Technology Ltd | Construction | 2019 |
| Oriental Delight Castleford Ltd | Hospitality | 2022 |
| Orvet UK | Professional & scientific | 1996 |
| Osagie House Ltd | Real estate | 2021 |
| Otif Logistics Limited | Transport & logistics | 2009 |
| Otium Apartments (Stocksbridge) Limited | Households | 2023 |
| OTM - on Track Marketing Ltd | Professional & scientific | 2024 |
| Overview Studios Ltd | Professional & scientific | 2019 |
| Oxfordshire Energy Partnerships Limited | Professional & scientific | 2020 |
| Oxide Stairs Limited | Manufacturing | 2025 |
| Ozzie Joinery Ltd | Other services | 2017 |
| P & W Site Fixing Limited | Manufacturing | 1995 |
| P. J. Anderson Motor Engineers Limited | Wholesale & retail | 1982 |
| Packo Inox Limited | Professional & scientific | 1938 |
| Papa Jav's Ltd | Hospitality | 2024 |
| Papaver Software Limited | Information & communication | 2019 |
| PAR Refrigeration and Air Conditioning Services Limited | Construction | 2012 |
| Parapet Holdings Ltd | Health & social care | 2023 |
| Parker Property Services Limited | Real estate | 2019 |
| Party Delights Limited | Wholesale & retail | 2023 |
| Paulosophy Aesthetics Ltd | Other services | 2025 |
| PBG Electrical Ltd | Construction | 2013 |
| PBG Interiors Ltd | Construction | 2020 |