| NOA Properties 25 Ltd | Real estate | 2026 |
| Nobles Casino Gaming Ltd | Arts & recreation | 2023 |
| Nolla Ltd | Information & communication | 2023 |
| NON Prophet HQ Ltd | Other services | 2021 |
| Noono Tech Ltd | Information & communication | 2025 |
| Norcliffe Hall Management Company Limited | Households | 2018 |
| Norfolk Investment and Services Limited | Real estate | 2021 |
| Norr Consultants Limited | Professional & scientific | 2010 |
| Norris Homes Ltd | Real estate | 2017 |
| North Devon Holidays Ltd | Hospitality | 2020 |
| North East Catering Supplies Ltd | Wholesale & retail | 2026 |
| North East Finishing Ltd | Other services | 2017 |
| North East Insulation (Newcastle) Limited | Wholesale & retail | 1975 |
| North East Wood Fabrication Ltd | Manufacturing | 2018 |
| North Staffordshire Landlords Association Limited | Administrative & support | 2002 |
| North Staffs Accident Repair Centre Ltd | Wholesale & retail | 2013 |
| North Staffs Accountancy Services Ltd. | Professional & scientific | 2003 |
| North Staffs Building & Joinery Contractors Ltd | Construction | 2012 |
| North Staffs Martial Arts & Wellbeing Centre CIC | Arts & recreation | 2026 |
| North Staffs Oatcake Bakers Limited | Manufacturing | 1965 |
| North Staffs.Caravans and Car Hire Limited | Other services | 1964 |
| North Western Civils Ltd | Construction | 2023 |
| Northcote Estates Limited | Real estate | 1999 |
| Northern Reporter Limited | Information & communication | 2017 |
| Northern Star Sports Ltd | Professional & scientific | 2019 |
| Northgate (NE) Limited | Households | 2020 |
| Northumbria Motor Group Limited | Wholesale & retail | 2026 |
| Nova Composites UK Limited | Wholesale & retail | 2020 |
| Nova Mechanical Ltd | Construction | 2017 |
| Novation Catering Ltd | Hospitality | 2003 |
| Novello Estates Limited | Construction | 2025 |
| Novellus Aesthetics Limited | Health & social care | 2019 |
| Noverel Ltd | Wholesale & retail | 2025 |
| Novo Threads Ltd | Wholesale & retail | 2025 |
| Nowsign Limited | Information & communication | 2019 |
| NP TM Ltd | Construction | 2025 |
| NPC Civils Ltd | Construction | 2016 |
| Nrjomolo Limited | Health & social care | 2020 |
| NS Electrical Services Staffordshire Limited | Construction | 2026 |
| NSK Properties Limited | Real estate | 2017 |
| NU TAN Tanning Ltd | Other services | 2024 |
| Nugelato Franchising Limited | Administrative & support | 2019 |
| Nugelato Icecream Manufacturing Co Limited | Manufacturing | 2016 |
| Nugelato Ltd | Manufacturing | 2015 |
| NUL Hotel Ltd | Hospitality | 2019 |
| NUL Property Ltd | Real estate | 2024 |
| NY World Ltd | Wholesale & retail | 2025 |
| O Spa London Ltd | Arts & recreation | 2009 |
| O'Hare Construction Ltd | Real estate | 2000 |
| O'Sullivan Environmental Ltd | Professional & scientific | 2024 |
| O'Tooles (NE) Ltd | Arts & recreation | 2017 |
| O.S. Housing Limited | Real estate | 2024 |
| OAJ Recruitment Ltd | Administrative & support | 2026 |
| Oak Court (Staffs) Limited | Real estate | 2014 |
| Oakley Psychology Service Ltd | Other services | 2017 |
| Oaklyn Laurel Group Limited | Financial services | 2024 |
| Oaktree Inc Limited | Real estate | 2016 |
| Oates Family AUM Ltd | Financial services | 2026 |
| Oaty Dough Ltd | Manufacturing | 2025 |
| Occasier Ltd | Administrative & support | 2026 |
| Occasions (NI) Limited | Wholesale & retail | 2013 |
| Occator Limited | Administrative & support | 2021 |
| Ocean Group Limited | Wholesale & retail | 2009 |
| Office Lettings Ltd | Real estate | 2019 |
| Offshore Stainless and Alloys Limited | Manufacturing | 2026 |
| Offshore Stainless Supplies Limited | Manufacturing | 2026 |
| OHO Ltd | Administrative & support | 2019 |
| OHP London Limited | Construction | 2014 |
| OJO Consultancy Limited | Information & communication | 2017 |
| Oktal Trading Ltd | Wholesale & retail | 2014 |
| Old Constabulary Property Management Limited | Households | 1999 |
| Old KIT BAG LLP | | 2011 |
| Old Mill Catering Ltd | Hospitality | 2021 |
| Old Oak Longridge Ltd | Hospitality | 2024 |
| Old Street Creations Ltd | Hospitality | 2024 |
| Oldacre Investments Ltd | Real estate | 2024 |
| Oldfield’S Gym Ltd | Arts & recreation | 2025 |
| Olinek Property Ltd | Real estate | 2020 |
| Omaq Interiors Limited | Administrative & support | 2010 |
| OMD Bricklaying Limited | Construction | 2017 |
| Omega Asbestos Consulting (Yorkshire) Ltd | Professional & scientific | 2022 |
| Omega Asbestos Consulting Limited | Professional & scientific | 2010 |
| Omega Property Group Ltd | Real estate | 2026 |
| OMH Consultancy Ltd | Professional & scientific | 2025 |
| Omnicert Ltd | Construction | 2025 |
| Omnifab Mobile Welding Limited | Manufacturing | 2024 |
| ON the Go Recycling Limited | Water & waste | 2010 |
| One James Street Management Company Limited | Real estate | 2008 |
| One Smarthome Limited | Other services | 2016 |
| One Stop Shop Traders Ltd | Wholesale & retail | 2024 |
| One Way Plumbing Limited | Construction | 2024 |
| Onestopsupplements Ltd | Arts & recreation | 2026 |
| Onsil Ltd | Professional & scientific | 2026 |
| Ontime Packaging Ltd | Wholesale & retail | 2026 |
| Onware Ltd | Wholesale & retail | 2025 |
| Opaewrpurse Ltd | Manufacturing | 2025 |
| Open Financial Limited | Information & communication | 2013 |
| Open Trust Asset Finance Ltd | Financial services | 2025 |
| Open Trust Commercials Limited | Wholesale & retail | 2026 |
| Optima Housing Ltd | Real estate | 2023 |