| Novam Sphere Limited | Professional & scientific | 2023 |
| Nrglobaltrading Ltd | Wholesale & retail | 2026 |
| NS PVC Ltd | Wholesale & retail | 2025 |
| NSM Care Ltd | Health & social care | 2014 |
| NSP Enterprise Ltd | Other services | 2025 |
| NT Careservices Limited | Administrative & support | 2026 |
| Nucleus Logistics Limited | Transport & logistics | 2014 |
| Nuke Betts Group Ltd | Construction | 2023 |
| Nuvo Investments UK Ltd | Hospitality | 2017 |
| NVQ APT Ltd | Professional & scientific | 2025 |
| O & B Machinery & Equipment Limited | Wholesale & retail | 2025 |
| O-Rae Products Ltd | Wholesale & retail | 2025 |
| Oakland Windows Limited | Construction | 2012 |
| Oaklodge Cars Limited | Wholesale & retail | 2021 |
| Oaktreerefurb Ltd | Construction | 2025 |
| OAS (2023) Limited | Professional & scientific | 2023 |
| Octomo Limited | Professional & scientific | 2025 |
| Oettingen GmbH | | 1988 |
| Olex Construction Ltd | Construction | 2024 |
| Olfi Freight Limited | Manufacturing | 2014 |
| Olinthus Construction Ltd | Administrative & support | 2025 |
| Oliver Services Ltd | Administrative & support | 2024 |
| OMC Driver Ltd | Transport & logistics | 2025 |
| Omega Homes and Developments Limited | Construction | 2016 |
| Omega Scaffolding Holdings Limited | Financial services | 2016 |
| Omega Scaffolding Solutions Limited | Construction | 2012 |
| Omex Electrical Ltd | Construction | 2025 |
| ON Site Powder Coat Services Limited | Administrative & support | 1998 |
| ON the Green Promotions Limited | Administrative & support | 2025 |
| One Best Delivery Ltd | Transport & logistics | 2025 |
| One Stop Builders Ltd | Construction | 2017 |
| One Stop Pharmacy Limited | Wholesale & retail | 2016 |
| One Stop Recovery Limited | Health & social care | 2023 |
| One Unity Initiative Ltd | Professional & scientific | 2026 |
| Online Behaviours Limited | Education | 2018 |
| Online Shopping Ltd | Wholesale & retail | 2023 |
| Only Team Ltd | Administrative & support | 2025 |
| Onplumb Ltd | Administrative & support | 2008 |
| Onsite Care Training Limited | Wholesale & retail | 2022 |
| Onsite Healthcare Ltd | Administrative & support | 2020 |
| Onsite International Limited | Administrative & support | 2022 |
| Onwards and Upwards Care Ltd | Health & social care | 2025 |
| Opal Cosmetics Ltd | Wholesale & retail | 2025 |
| Opaque Decorators Limited | Construction | 2001 |
| Opitzway Ltd | Transport & logistics | 2026 |
| OPW Developments Ltd | Construction | 2025 |
| Orchard Social Housing Ltd | Real estate | 2024 |
| Osil (Poland) Limited | Professional & scientific | 2011 |
| Oskhomes Ltd | Real estate | 2019 |
| Otos & VOI Limited | Hospitality | 2023 |
| Otto Maintenance Ltd | Administrative & support | 2025 |
| Oval Racing Supplies Ltd | Wholesale & retail | 2026 |
| Oven Tech Ltd | Extraterritorial | 2025 |
| Ozim Stores Ltd | Wholesale & retail | 2024 |
| P & C Engineering Limited | Manufacturing | 2007 |
| P B Fire Protection Ltd | Construction | 2019 |
| P L H Engineering Limited | Manufacturing | 2016 |
| P P N Property Ltd | Real estate | 2026 |
| P Westwood Properties Limited | Real estate | 2024 |
| Pabla Impex Ltd | Wholesale & retail | 2018 |
| Packridge Ltd | Real estate | 2024 |
| Padda Property Group Ltd | Real estate | 2024 |
| Pafomen Company Limited | Construction | 2023 |
| Pahari Property Ltd | Real estate | 2024 |
| Pallet Point Limited | Wholesale & retail | 2023 |
| Pallet Racking Systems Ltd | Construction | 2001 |
| Palmal Properties Limited | Real estate | 2022 |
| Palmyra Health Care Solutions Ltd | Public administration | 2023 |
| Pamasa Ltd | Health & social care | 2026 |
| Panesar Kitchen & Bedrooms Ltd | Construction | 2023 |
| Pangli Productions Limited | Information & communication | 2014 |
| Panjab Construction Group Ltd | Construction | 2018 |
| Panjab Haulage Limited | Transport & logistics | 2025 |
| Pannu Logistics Solutions Ltd | Transport & logistics | 2026 |
| Pannu Transport Ltd | Transport & logistics | 2019 |
| Papiah Limited | Construction | 2025 |
| Para Group Holdings Limited | Financial services | 2022 |
| Paradise Childrens Wear Limited | Administrative & support | 1997 |
| Paragon Childcare Services Ltd | Health & social care | 2020 |
| Param Transport Ltd | Transport & logistics | 2024 |
| Paramount Children Care Ltd | Health & social care | 2020 |
| Paranoid Guitars Limited | Other services | 2025 |
| Parbail Limited | Hospitality | 2025 |
| Paris Carpets Flooring Limited | Construction | 2016 |
| Park Street (AGG3) Ltd | Real estate | 2013 |
| Parkbrook Bar and Grill Limited | Hospitality | 2015 |
| Parker Wright Consulting Limited | Professional & scientific | 2009 |
| Partineez Events Ltd | Arts & recreation | 2024 |
| PASS4FUN Limited | Education | 2011 |
| Paul & Company Healthcare Limited | Health & social care | 2021 |
| Paul Worrallo Electrical Services Ltd | Construction | 2016 |
| Payeee Limited | Information & communication | 2024 |
| PB Recovery & Storage Ltd | Transport & logistics | 2022 |
| PB02ASR Limited | Transport & logistics | 2022 |
| PB08 Transport Ltd | Transport & logistics | 2024 |
| PBX Haulage Ltd | Transport & logistics | 2022 |
| PCC Property Holdings Limited | Real estate | 2017 |
| Peak Performance Engineers Ltd | Manufacturing | 2016 |
| Pearl Concrete Finishers Ltd | Construction | 2020 |
| Pearl Fashion Jewellery Ltd | Wholesale & retail | 2021 |