| Midland Rubber Co. Limited(The) | Wholesale & retail | 1934 |
| Mileham Science Limited | Real estate | 2013 |
| Milla Boutique Ltd | Wholesale & retail | 2011 |
| Misadani Limited | Real estate | 2010 |
| Mishra and Singh Ltd | Real estate | 2023 |
| MJM Brigg Limited | Real estate | 2014 |
| MJM Healthcare Limited | Health & social care | 2023 |
| MJM Holdings Corporation Limited | Financial services | 2023 |
| MJM Skin Ltd | Health & social care | 2013 |
| Mooney Motorsport Ltd | Professional & scientific | 2025 |
| Mortimer Print Limited | Manufacturing | 2006 |
| Motorlease (UK) Limited | Wholesale & retail | 2002 |
| Motorlease Holdings Limited | Financial services | 2022 |
| MPB Installations Limited | Construction | 2005 |
| MRN Print.Com Limited | Manufacturing | 2014 |
| Muriel Nandita Michael Limited | Health & social care | 2015 |
| Muted Farquharson Properties Ltd | Real estate | 2017 |
| Muthukumar Limited | Health & social care | 2012 |
| My Belle Boutique Ltd | Wholesale & retail | 2020 |
| N. R. Burnett Limited | Wholesale & retail | 1941 |
| Nashra Healthcare Solutions Limited | Health & social care | 2016 |
| Nasima Estates Ltd | Real estate | 2022 |
| NBM Training Ltd | Education | 2025 |
| ND Plastics Direct Limited | Wholesale & retail | 2013 |
| Networth Data Ltd | Information & communication | 2004 |
| New Cabin Space Ltd | Wholesale & retail | 2024 |
| Neway Contracts Limited | Wholesale & retail | 2004 |
| Newgate Estate (Hackness) Limited | Real estate | 2003 |
| Newtechwood Distribution UK Ltd | Wholesale & retail | 2019 |
| Nightknight Limited | Real estate | 2019 |
| Nord London Ltd | Wholesale & retail | 2025 |
| North Ferriby Football Club Limited | Arts & recreation | 2017 |
| Northbank Demolition Company Limited | Construction | 2000 |
| Northfield Healthcare Ltd | Wholesale & retail | 2020 |
| Novia Works Ltd | Information & communication | 2021 |
| Novosi Ltd | Real estate | 2020 |
| NSR Health Care Limited | Health & social care | 2023 |
| Nucleus Consultancy Ltd | Administrative & support | 2025 |
| Oak Court Land Trading Limited | Construction | 2019 |
| Oceanway Developments Limited | Transport & logistics | 2007 |
| Ocular Consultations Ltd | Health & social care | 2024 |
| Ogilvy & Wright Ltd | Hospitality | 2025 |
| Omnium Driffield Limited | Real estate | 1985 |
| Omya Specialty Materials (UK) Limited | Wholesale & retail | 2026 |
| Omya UK Limited | Manufacturing | 1947 |
| ON the Hedge Ltd | Administrative & support | 2024 |
| Onuba Comms Ltd | Professional & scientific | 2021 |
| OOH! Review Ltd | Professional & scientific | 2014 |
| Oomph Made Limited | Manufacturing | 2000 |
| Ophthalmic Consultations Ltd | Health & social care | 2022 |
| Ordco Ltd | Hospitality | 2025 |
| Organic Nurseries Ferriby Ltd | Agriculture & fishing | 2023 |
| Origin Healthcare Services Ltd | Administrative & support | 2021 |
| Origin Packaging Global Ltd | Financial services | 2025 |
| Origin Packaging Limited | Manufacturing | 2009 |
| Oryx Fine Design Ltd | Wholesale & retail | 2021 |
| P&D Property Maintenance Limited | Construction | 2023 |
| P.A.S.S. Property Care Ltd | Other services | 2018 |
| Paragon Packaging Company | Manufacturing | 2013 |
| Paragon Packaging Global Ltd | Financial services | 2025 |
| Paris Salon Limited | Other services | 2022 |
| Park Lane (Swanland) Management Co Limited | Professional & scientific | 2012 |
| Pattern Passion Ltd | Wholesale & retail | 2015 |
| Paul Dykes Electrical & Security Systems Limited | Construction | 2004 |
| PEA Catering Ltd | Hospitality | 2021 |
| Pear Distribution Limited | Wholesale & retail | 2026 |
| Pearson Holdings & Investments Ltd | Financial services | 2022 |
| PEN5 Ltd | Professional & scientific | 2009 |
| Pencas Ltd | Other services | 2024 |
| Peter Walker Engineering Limited | Manufacturing | 2002 |
| Petrochemical Technical Services Ltd | Administrative & support | 2006 |
| Pipe and Cable Ltd | Other services | 2016 |
| Planet Igloo Limited | Real estate | 2004 |
| Planet-Promo.World Limited | Professional & scientific | 2003 |
| Ploutos Capital Limited | Real estate | 2013 |
| Pluss-Staufer Limited | Manufacturing | 1995 |
| Pmcl Property Ltd | Real estate | 2025 |
| POP Group (Europe) Ltd | Manufacturing | 2007 |
| Positive Action Publications Limited | Information & communication | 1987 |
| Poweronplatforms Limited | Information & communication | 2013 |
| Ppala's Anaesthesia Limited | Health & social care | 2022 |
| PPR Anaesthetic Services Ltd | Health & social care | 2016 |
| PRC Property Investments Ltd | Real estate | 2021 |
| PRC Services Ltd | Transport & logistics | 2019 |
| PRC Tyre Distribution Ltd | Wholesale & retail | 2024 |
| Preemptive Safety Solutions Limited | Construction | 2025 |
| Premier Animation Limited | Wholesale & retail | 2007 |
| Premier Electrical (Hull) Ltd | Other services | 2008 |
| Prezey Ltd | Wholesale & retail | 2021 |
| Pritchard Production Management Ltd | Administrative & support | 2013 |
| Pro CUT Tooling Limited | Manufacturing | 2003 |
| Profound Technologies Limited | Information & communication | 2022 |
| Property Agent Support Services Ltd | Real estate | 2015 |
| Propertyoz Limited | Real estate | 2016 |
| Puneeth Consultants Ltd | Information & communication | 2023 |
| QA Lettings Limited | Real estate | 2017 |
| QCH Rotherham Limited | Construction | 2020 |
| Qdos Education Limited | Education | 2015 |
| Qdos Student Homes Limited | Real estate | 2005 |
| Qonnan Limited | Health & social care | 2015 |