| Nolm Limited | Construction | 2021 |
| Nomad Archives Ltd | Wholesale & retail | 2024 |
| Nomi Car Traders Ltd | Wholesale & retail | 2023 |
| Noodleshut Ltd | Hospitality | 2025 |
| Noor Barbers Ltd | Other services | 2026 |
| Noor Hub Ltd | Hospitality | 2026 |
| Noor Motors Limited | Wholesale & retail | 2025 |
| Noor Trading Ltd | Manufacturing | 2026 |
| Noor&Sany Ltd | Hospitality | 2024 |
| Noretail.Co.Uk Limited | Manufacturing | 2021 |
| Norfa Ltd | Wholesale & retail | 2021 |
| Nori Management Ltd | Professional & scientific | 2023 |
| Norocel Facades Ltd | Construction | 2025 |
| North South Installs Ltd | Transport & logistics | 2025 |
| Norwood Food Investments Ltd | Hospitality | 2026 |
| Noslink Ltd | Extraterritorial | 2024 |
| Nouman Enterprises Ltd | Transport & logistics | 2025 |
| Nourish Nook Ltd | Construction | 2023 |
| Novac Drywall Ltd | Construction | 2024 |
| Novadeals Hub Ltd | Wholesale & retail | 2024 |
| Novamoor Limited | Other services | 2012 |
| Novasera Homes Ltd | Health & social care | 2023 |
| Novasera Limited | Real estate | 2019 |
| Novastroy Ltd | Construction | 2025 |
| Novasys Advisory Ltd | Professional & scientific | 2025 |
| Novenza Global Limited | Wholesale & retail | 2025 |
| Novotech 365 Limited | Construction | 2025 |
| Novus Eco Green Roofs Limited | Construction | 2019 |
| Nozzle Alchemy Ltd | Wholesale & retail | 2023 |
| NP Niki Services Limited | Water & waste | 2019 |
| NPD24 Ltd | Wholesale & retail | 2026 |
| Npire EXE Ltd | Information & communication | 2022 |
| Npoint Surveying Ltd | Professional & scientific | 2025 |
| NR Trend Ltd | Wholesale & retail | 2025 |
| NRM Developments Ltd | Real estate | 2013 |
| NS Contractors London Ltd | Construction | 2016 |
| NSV Homes Ltd | Construction | 2019 |
| NT Imports London Limited | Wholesale & retail | 2012 |
| Nucta Formations Ltd | Wholesale & retail | 2026 |
| Nujak&Chikel Enterprises Limited | Construction | 2017 |
| NUMB1 Ltd | Construction | 2021 |
| NUMBER1 Developers Ltd | Construction | 2023 |
| Numverse Accountants Ltd | Professional & scientific | 2025 |
| Numyn Labs Limited | Information & communication | 2026 |
| Nur's House Ltd | Real estate | 2020 |
| Nurah Yasir Ltd | Administrative & support | 2025 |
| Nurakeem Services Limited | Health & social care | 2023 |
| Nursing Services Ltd | Health & social care | 2024 |
| Nusair Group Ltd | Wholesale & retail | 2017 |
| Nutracity Ltd | Health & social care | 2014 |
| Nuvia Developments Ltd | Hospitality | 2025 |
| Nvc&Mc Electrical Ltd | Construction | 2018 |
| Nwinn International Consultancy Ltd | Professional & scientific | 2024 |
| Nxted Ltd | Education | 2024 |
| Nyamuga Limited | Real estate | 2018 |
| NYC Services Ltd | Transport & logistics | 2026 |
| Nyck&Ani Ltd | Construction | 2018 |
| Nymb Payroll Services Ltd | Professional & scientific | 2015 |
| O & a Ltd | Construction | 2015 |
| O & D Plastering & Rendering Limited | Construction | 2015 |
| O & M Global Ventures Ltd | Health & social care | 2014 |
| O S Unique Ltd | Administrative & support | 2016 |
| O Timothy Electrical Limited | Construction | 2014 |
| O U Care and Cleaning Limited | Health & social care | 2025 |
| O Z Motors Ltd | Wholesale & retail | 2021 |
| O'Jessy Healthcare Services Limited | Health & social care | 2014 |
| O'Shay Ltd | Wholesale & retail | 2019 |
| O.T Atelier Ltd | Manufacturing | 2026 |
| O3 Concept Ltd | Construction | 2024 |
| O5IVE Limited | Professional & scientific | 2018 |
| Oaak Ltd | Wholesale & retail | 2023 |
| Oak & Sons Waterproofing Ltd | Construction | 2026 |
| Oak Tree Retail (Anglia) Limited | Wholesale & retail | 2014 |
| Oakstream Limited | Health & social care | 2019 |
| Oasis at Dafil Limited | Real estate | 2025 |
| Obaasima's Kitchen Ltd | Wholesale & retail | 2021 |
| OBI1 Consulting Ltd | Financial services | 2018 |
| Obinna Ltd | Health & social care | 2017 |
| Obli Consultants Limited | Other services | 2016 |
| Oblivion Nation Ltd | Wholesale & retail | 2015 |
| Oboisey Ltd | Other services | 2020 |
| Obsid Limited | Information & communication | 2026 |
| OCA Construction Ltd | Construction | 2023 |
| OCA Installation Ltd | Construction | 2025 |
| Ocean Fish Bar (Dagenham) Limited | Hospitality | 2020 |
| Ocean Music Entertainment Ltd | Information & communication | 2014 |
| Ocean Recycling Limited | Water & waste | 2025 |
| Ocean Security Services Ltd | Administrative & support | 2020 |
| Ocitoh Ltd | Construction | 2017 |
| Octopus Transport and Removals Ltd | Transport & logistics | 2020 |
| Odera Ltd | Health & social care | 2023 |
| Odilile Jonathan Services Ltd | Health & social care | 2015 |
| Odin Dryliner Ltd | Construction | 2021 |
| ODL Solutions Limited | Administrative & support | 2015 |
| Odogwu Cash & Carry Food Limited | Wholesale & retail | 2025 |
| ODS Construction Ltd | Construction | 2018 |
| OF Rashid High Tickets Ltd | Professional & scientific | 2025 |
| OFF Square Ltd | Other services | 2025 |
| OFF the Corner Ltd | Wholesale & retail | 2019 |
| Offer Oasis Ltd | Wholesale & retail | 2025 |