| North Stride Ltd | Information & communication | 2025 |
| Nova Consultants Prime Ltd | Wholesale & retail | 2018 |
| Npower Solutions Limited | Information & communication | 2008 |
| NR Crest Advisory Ltd | Professional & scientific | 2024 |
| NSK Geras Limited | Construction | 2022 |
| Nuevo Coaches Ltd | Transport & logistics | 2018 |
| Nupremo Ltd | Professional & scientific | 2019 |
| NUTRA144PT Ltd | Arts & recreation | 2023 |
| Nuts & Bolts Property Solutions Ltd | Construction | 2020 |
| Nuvutrade Limited | Wholesale & retail | 2026 |
| NWM Vehicles Limited | Information & communication | 2026 |
| NZB Services Limited | Other services | 2016 |
| O Munir Consulting Ltd | Education | 2021 |
| O&E Maintenance & Services Ltd | Households | 2025 |
| O.S Legal Ltd | Professional & scientific | 2022 |
| Oakline Real Estate Limited | Real estate | 2025 |
| Oakman Motors Limited | Wholesale & retail | 2019 |
| Oakstone Digital Ltd | Information & communication | 2026 |
| Oana MAY Ltd | Information & communication | 2023 |
| OBE Ltd | Professional & scientific | 2024 |
| Obhg Property Group Limited | Hospitality | 2025 |
| Obico Ltd | Real estate | 2026 |
| Obrim Ltd | Health & social care | 2024 |
| Ocean DRY Cleaners Limited | Other services | 2023 |
| Oceaner LLP | | 2025 |
| Oceaning Ltd | Extraterritorial | 2025 |
| Octavolt Ltd | Construction | 2025 |
| Oddrods Ltd | Wholesale & retail | 2024 |
| Odiom Limited | Wholesale & retail | 2025 |
| Ofanojobslinks Limited | Administrative & support | 2016 |
| Okibe Haircare Ltd | Wholesale & retail | 2024 |
| Olinabu Care Services Ltd | Public administration | 2025 |
| Olympus ICT Limited | Information & communication | 2015 |
| OM Gardens Ltd | Wholesale & retail | 2024 |
| Omar AAI Limited | Health & social care | 2023 |
| Omega Analytica Ltd. | Information & communication | 2020 |
| Omega Consult Ltd | Professional & scientific | 2024 |
| Omnipotent Consultants Ltd | Professional & scientific | 2018 |
| Omnis Supply Ltd | Wholesale & retail | 2019 |
| Omobel's Kitchen Ltd | Hospitality | 2024 |
| Omvera Ltd | Wholesale & retail | 2026 |
| ON Point Painters Ltd | Construction | 2025 |
| ON the Move Limited | Transport & logistics | 2009 |
| ON Time Parcel Limited | Wholesale & retail | 2016 |
| ON Writes Ltd | Arts & recreation | 2021 |
| One Akira Limited | Real estate | 2022 |
| One Direction Chauffeuring Ltd | Transport & logistics | 2023 |
| Onefullying Ltd | Wholesale & retail | 2025 |
| Oneofoneldn Ltd | Wholesale & retail | 2025 |
| Online Airport Transfers Ltd | Transport & logistics | 2018 |
| Ontime Chauffeurs Ltd | Transport & logistics | 2017 |
| Ontime Executives Ltd | Transport & logistics | 2020 |
| Onyx Beauty Bar Ltd | Other services | 2019 |
| Oofy Limited | Transport & logistics | 2024 |
| Oosby Ltd | Information & communication | 2026 |
| Openworld Escapes Limited | Administrative & support | 2026 |
| Oprea Carpentry Ltd | Manufacturing | 2020 |
| OPS Financial Advice Limited | Financial services | 2021 |
| Optima Performance (Elite X) Ltd | Health & social care | 2018 |
| ORA Salon Ltd | Other services | 2026 |
| Orane Beauty Ltd | Other services | 2023 |
| ORC Property Ltd | Real estate | 2018 |
| Orchards Pharmacy Limited | Wholesale & retail | 2002 |
| Ordinal Soft Limited | Information & communication | 2014 |
| Orestis.Transport Ltd | Transport & logistics | 2020 |
| Original Burger Boys Ltd | Hospitality | 2026 |
| Original Note Ltd | Information & communication | 2026 |
| OS Law Ltd | Professional & scientific | 2025 |
| Oscars London Homes Ltd | Real estate | 2018 |
| Osmy Limited | Real estate | 2002 |
| Otha 2 Limited | Hospitality | 2025 |
| Otha 3 Limited | Hospitality | 2025 |
| Otha Ltd | Hospitality | 2024 |
| Ottoman Solutions Ltd | Wholesale & retail | 2018 |
| Ovidiu Munteanu Ltd | Transport & logistics | 2025 |
| OVN Ltd. | Information & communication | 2025 |
| OZ Construction Ltd | Construction | 2020 |
| Ozair Trding Ltd | Wholesale & retail | 2025 |
| P G and Sons Ltd | Transport & logistics | 2015 |
| P&K Moore Productions Ltd | Construction | 2019 |
| P1 Couriers Ltd | Transport & logistics | 2024 |
| P5 Chauffeur's Ltd | Transport & logistics | 2026 |
| PA 80 Ltd | Other services | 2017 |
| Pace Vita Limited | Wholesale & retail | 2021 |
| PAD Pro Limited | Real estate | 2019 |
| PAK Airways Limited | Administrative & support | 2016 |
| Palace Tandoori WD Ltd | Hospitality | 2018 |
| Panache Candles Ltd | Wholesale & retail | 2026 |
| Pannu Investment Limited | Real estate | 2025 |
| Pannu Products Ltd | Wholesale & retail | 2020 |
| Pannu Properties Limited | Real estate | 2019 |
| Pano Building Services Ltd | Construction | 2022 |
| Park, Store & Live Ltd | Transport & logistics | 2023 |
| Parkins Care Angels Limited | Health & social care | 2012 |
| Parma Group Ltd | Real estate | 2018 |
| Parthi Design and Consultants Limited | Professional & scientific | 2023 |
| Partners Cleaning and Maintenance Services Ltd | Other services | 2024 |
| Parvion Tech Ltd | Information & communication | 2025 |
| Parx Ltd | Manufacturing | 2021 |
| Pathway Tuition Ltd | Education | 2018 |