| Little Love Lane Pre-School and Nursery CIC | Education | 2021 |
| Live Like This Ltd | Wholesale & retail | 2013 |
| LMA Heritage Consultancy Limited | Professional & scientific | 2023 |
| LMH Creative Ltd | Professional & scientific | 2026 |
| Logic OPS Ltd | Information & communication | 2025 |
| Lonefox Technical Services Limited | Construction | 2025 |
| Long Dog Art Ltd | Wholesale & retail | 2022 |
| Long Dog Fashion Ltd | Wholesale & retail | 2022 |
| Long Dog Records Ltd | Wholesale & retail | 2026 |
| Long Dog Treasures Ltd. | Wholesale & retail | 2020 |
| Lpiwuk Ltd | Information & communication | 2019 |
| Lumanation Ltd | Arts & recreation | 2025 |
| Luxline Exterior Cleaning Ltd | Administrative & support | 2025 |
| LV Ingrams Holdings Limited | Financial services | 2001 |
| LWA (IW) Limited | Professional & scientific | 2022 |
| Lyon & Turnbull Holdings Limited | Financial services | 2024 |
| M. Greville & Co LLP | | 2015 |
| Mackinnon (EFS) LLP | | 2011 |
| Mackinnon Investments Limited | Financial services | 2012 |
| Mackinnon SPV 3 LLP | | 2011 |
| Mackinnon SPV Funding LLP | | 2011 |
| Mackinnon SPV2 LLP | | 2011 |
| Maggie Allen at Andrew Ross Limited | Other services | 2019 |
| Malibu Ice Limited | Wholesale & retail | 2021 |
| Manesty Solutions Ltd | Professional & scientific | 2013 |
| Marblehead Limited | Real estate | 2018 |
| Marine Store Cowes Limited | Transport & logistics | 2026 |
| Marine View Close Management Company Limited | Households | 2016 |
| Marine Welding and Inspection Services Ltd | Manufacturing | 2016 |
| Marine Welding Services Limited | Manufacturing | 2022 |
| Marinus Freehold Limited | Households | 2009 |
| Marinus Residents Management Company Limited | Households | 2006 |
| Marshall Brown Creations Ltd | Wholesale & retail | 2024 |
| Marshall C.K.G. Composites Limited | Manufacturing | 2008 |
| Marvins Holdings Limited | Real estate | 2019 |
| Match My Bricks Ltd | Wholesale & retail | 2026 |
| MAX Richardson Marine Ltd | Manufacturing | 2022 |
| MAX West Enterprises UK Limited | Wholesale & retail | 2023 |
| Maynard Consulting Limited | Professional & scientific | 2023 |
| MB Medical Resources Ltd | Manufacturing | 2023 |
| Mcbride Property Investment Group Ltd | Real estate | 2025 |
| Mcintosh Electrical Limited | Construction | 2025 |
| MDX Trading Limited | Other services | 2021 |
| Meaningful Planet Ltd | Information & communication | 2023 |
| Medham Farm Estates Limited | Agriculture & fishing | 2012 |
| Medina Content Group Ltd | Information & communication | 2019 |
| Medina Creamery Ltd | Hospitality | 2026 |
| Medina Publishing Limited | Information & communication | 2009 |
| Megan Baker Limited | Real estate | 2005 |
| Mentor Members Ltd | Administrative & support | 2025 |
| Mermaid Holidays IOW Ltd | Hospitality | 2025 |
| Merrie Gardens Rentals Limited | Real estate | 2020 |
| Meteor Cowes Limited | Real estate | 2025 |
| Mettle and Byte Ltd | Manufacturing | 2023 |
| Mexut Ltd | Other services | 2025 |
| Miami Beach (Sutton on Sea) Limited | Real estate | 1960 |
| Middleton Court (IW) Management Company Limited | Professional & scientific | 2011 |
| Midmoor Trading Company Limited | Professional & scientific | 2002 |
| Miles Blamire Limited | Construction | 2020 |
| Mills Marine Group Limited | Financial services | 2022 |
| Mitchell Steele Blade Repairs Limited | Manufacturing | 2022 |
| MJR (Health & Safety) Associates LLP | | 2020 |
| MK Scaffolding Hire & Sales Limited | Construction | 2026 |
| MK Scaffolding IOW Ltd | Construction | 2024 |
| Monterey Avocet Ltd | Hospitality | 2024 |
| Monterey Egypt Point Ltd | Hospitality | 2024 |
| Monterey Turnstone Ltd | Hospitality | 2024 |
| Mornington Mews RTM Company Limited | Households | 2025 |
| Moss Accounting Ltd | Professional & scientific | 2021 |
| Myles Brown Ltd | Wholesale & retail | 2025 |
| NCR Holdings (IW) Limited | Professional & scientific | 2026 |
| Neon EGG Ltd | Manufacturing | 2019 |
| Nermine Taylor Estates Limited | Real estate | 2023 |
| Netguides Limited | Information & communication | 1996 |
| Newport Business Supplies Ltd | Wholesale & retail | 2025 |
| Newseas Trading Limited | Wholesale & retail | 1993 |
| Nexitech Ltd | Information & communication | 2026 |
| Next Generation Events Limited | Administrative & support | 2007 |
| Nexus Fabrications Limited | Manufacturing | 2016 |
| Nexus HE Systems Limited | Information & communication | 2026 |
| Nixworx Designs Ltd | Professional & scientific | 2024 |
| Noon PR Limited | Professional & scientific | 2025 |
| Noonsite Limited | Information & communication | 2010 |
| Northstar Specialist Vehicle Conversions Limited | Manufacturing | 2017 |
| Northwood House Charitable Trust Company Limited | Hospitality | 2012 |
| Northwood House Trading Company Limited | Hospitality | 2017 |
| Northwood Primary School Academy Trust | Education | 2013 |
| Nortonn Limited | Wholesale & retail | 2025 |
| Notp Investment Limited | Real estate | 2023 |
| NT Commercial Limited | Administrative & support | 2023 |
| O Wyld Engineering Ltd | Manufacturing | 2014 |
| Oak Management Limited | Real estate | 2000 |
| Obow LLP | | 2018 |
| Oceantech Limited | Professional & scientific | 1987 |
| Oceantech Marine Limited | Transport & logistics | 1989 |
| Oceantech-Datawatt Limited | Extraterritorial | 2000 |
| Octe Limited | Information & communication | 2024 |
| Offshore Instruments Limited | Manufacturing | 1986 |
| Olesinski Limited | Professional & scientific | 2016 |
| ON OFF Road Repairs Ltd | Wholesale & retail | 2016 |