| Nest Books Limited | Administrative & support | 2025 |
| Nestloop Limited | Information & communication | 2025 |
| Nestmeadow Limited | Health & social care | 2025 |
| Netbizr Limited | Wholesale & retail | 2022 |
| Network and Data World Solutions (Ndws) Ltd | Information & communication | 2024 |
| Neuro Motor Group Ltd | Wholesale & retail | 2025 |
| New Begining Care Company Limited | Health & social care | 2021 |
| New GEN Learners Ltd | Education | 2021 |
| New Insight Educational Services Limited | Education | 2020 |
| New Leaf Developers Ltd | Real estate | 2025 |
| New Road MOT Testing Station Ltd | Wholesale & retail | 2022 |
| New Road Pro Cars Ltd | Wholesale & retail | 2025 |
| New Spec Interiors Ltd | Construction | 2024 |
| New Trendz Limited | Professional & scientific | 2014 |
| New Tyre Warehouse Ltd | Wholesale & retail | 2014 |
| Newgroundglobal Limited | Administrative & support | 2025 |
| Newton Equipment Limited | Manufacturing | 2001 |
| Newton Orwell Properties Ltd | Real estate | 2019 |
| Newton Science Limited | Manufacturing | 2018 |
| Nexacode Global Limited | Information & communication | 2025 |
| Nexconcept Limited | Information & communication | 2010 |
| Next Level Mechanic Limited | Wholesale & retail | 2022 |
| Nextmove Business Ltd | Transport & logistics | 2024 |
| Nhak & Co Ltd | Other services | 2019 |
| Nhat Minh Beauty Ltd | Other services | 2018 |
| Nica Ltd | Health & social care | 2021 |
| Nicorici Holdings Limited | Financial services | 2015 |
| Nigeria Art Society (UK) Ltd | Arts & recreation | 2013 |
| Nihal Heath Care Limited | Health & social care | 2019 |
| Nillaspice Creations Ltd | Agriculture & fishing | 2024 |
| Nilova Ltd | Wholesale & retail | 2026 |
| Ninth Cloud Solutions Ltd | Information & communication | 2025 |
| Nirmal UK Builder Limited | Construction | 2020 |
| NM Design 68 Ltd | Manufacturing | 2012 |
| Nobilis Group Ltd | Manufacturing | 2017 |
| Noemi Trans Ltd | Transport & logistics | 2019 |
| Noir Logistic Ltd | Transport & logistics | 2024 |
| Nordic Trader Limited | Wholesale & retail | 2025 |
| Norris Bedding Limited | Manufacturing | 1998 |
| North London Gymnastics Academy Ltd | Education | 2023 |
| Northfleet Transport Ltd | Transport & logistics | 2026 |
| Nourishment East Limited | Manufacturing | 2023 |
| Nrla Construction Ltd | Construction | 2020 |
| NS Fresh VEG Limited | Wholesale & retail | 2015 |
| NST Trading Ltd | Wholesale & retail | 2020 |
| NT Recovery Ltd | Wholesale & retail | 2025 |
| NTA Accountancy & Tax Ltd | Professional & scientific | 2020 |
| NTA Investment Limited | Administrative & support | 2022 |
| Nuhur Limited | Construction | 2012 |
| Nuqi Software Limited | Information & communication | 2024 |
| Nurenewables Heating Ltd | Construction | 2026 |
| Nurture Waves Ltd | Administrative & support | 2024 |
| Nurtured Community Care Ltd | Health & social care | 2025 |
| Nusraat Fareeha Ltd | Real estate | 2025 |
| NV4EVENTS Limited | Hospitality | 2019 |
| NVP Investments Ltd | Real estate | 2018 |
| NXT GEN ENT Ltd | Manufacturing | 2026 |
| Nyzas Ltd | Wholesale & retail | 2026 |
| NZ Engines Limited | Wholesale & retail | 2017 |
| NZ Property Limited | Real estate | 2022 |
| NZ Services Limited | Transport & logistics | 2021 |
| O S Commercial Consultancy Ltd | Professional & scientific | 2025 |
| OAF Services Ltd | Information & communication | 2021 |
| Oak-House Ltd | Construction | 2016 |
| Oakhouse Building Services Ltd | Construction | 2016 |
| Oasis Property Ventures Ltd | Real estate | 2017 |
| Oasis TEC Property Ltd | Real estate | 2024 |
| Obadiah Network Ltd | Extraterritorial | 2020 |
| Obadiah Studios Ltd | Extraterritorial | 2020 |
| Obidora Ltd | Real estate | 2022 |
| Obsessed Art Ltd | Arts & recreation | 2023 |
| Ocean E-Com Ltd | Wholesale & retail | 2025 |
| Ocran Homes Ltd | Real estate | 2022 |
| ODD Shape Ltd | Wholesale & retail | 2019 |
| OFB Solutions Ltd | Professional & scientific | 2022 |
| Office Assistants Ltd | Administrative & support | 2012 |
| OJ Matthew Limited | Other services | 2017 |
| Ojayriaz Ltd | Real estate | 2024 |
| Okeowo Locum Services Ltd | Wholesale & retail | 2022 |
| Okker Limited | Wholesale & retail | 2006 |
| Okwdesigns Ltd | Professional & scientific | 2026 |
| Olagunju Property Consortium (OPC) Limited | Real estate | 2019 |
| Olamuyex Limited | Wholesale & retail | 2013 |
| Olexify Solutions Limited | Administrative & support | 2023 |
| Olikesmi Limited | Health & social care | 2023 |
| Olivari LLP | | 2007 |
| Olivari UK Limited | Extraterritorial | 2000 |
| Olivia Motors Ltd | Wholesale & retail | 2021 |
| OLV Interiors Ltd | Construction | 2023 |
| OMB Estates Ltd | Real estate | 2022 |
| Omni Autos Ltd | Wholesale & retail | 2022 |
| Omni Service Provider Ltd | Administrative & support | 2022 |
| Omoboriowo Cargo and Logistics Ltd | Administrative & support | 2025 |
| Omolade's House Limited | Financial services | 2018 |
| Omu-Aran Development Community UK Chapter CIC | Professional & scientific | 2020 |
| ON Albion Holdings (UK) Limited | Financial services | 2024 |
| ON Albion Music Company (UK) Limited | Information & communication | 2024 |
| ON Site Services South East Ltd | Construction | 2023 |
| ON the Way Ltd | Transport & logistics | 2026 |
| One Driving School Limited | Education | 2007 |