| Marlon Jacob &David Properties Limited | Real estate | 2022 |
| Marshbank Management Ltd | Professional & scientific | 2006 |
| Marshlease Limited | Real estate | 1993 |
| Meadway Court Property Company Limited | Real estate | 2001 |
| Media Watch Limited | Other services | 2015 |
| Mentoa Limited | Other services | 2015 |
| Meonstoke Limited | Other services | 1996 |
| Meredith Consulting Limited | Other services | 2011 |
| MFP Group PLC | Financial services | 2003 |
| MH Intelligence (UK) Ltd. | Professional & scientific | 2014 |
| Middle Block Orpington Mansions Limited | Households | 2008 |
| Mill Hill Estates Limited | Real estate | 1998 |
| Mill Hill School Enterprises | Arts & recreation | 1983 |
| Mindsprings Partnership Limited | Arts & recreation | 2003 |
| Minos Investments Limited | Extraterritorial | 1973 |
| MKL Consultants Limited | Other services | 2010 |
| Mountney Limited | Wholesale & retail | 1979 |
| Msbbq Ltd | Hospitality | 2019 |
| Museprime Management Limited | Professional & scientific | 2004 |
| Museprime Properties Limited | Real estate | 1984 |
| Myhr Resources Limited | Other services | 2013 |
| NAM PAI Chuan Trading Limited | Arts & recreation | 2006 |
| Nasher Limited | Manufacturing | 1997 |
| NET Control | | 2001 |
| Nethome-Link | | 2001 |
| Newcon London Ltd | Construction | 2026 |
| Nigerbird Engineering Limited | Professional & scientific | 2025 |
| Njav Limited | Professional & scientific | 2016 |
| NMS Coaching Limited | Professional & scientific | 2020 |
| NON Stop Action Ltd | Wholesale & retail | 2018 |
| NON Stop Sports Education Ltd | Education | 2015 |
| Northridge Estates Limited | Real estate | 1995 |
| Nountra Consultants Limited | Professional & scientific | 2015 |
| NTS Health Ltd. | Professional & scientific | 2014 |
| O Legal Limited | Professional & scientific | 2024 |
| Obang Holdings Ltd | Real estate | 2024 |
| OH Squirrel Limited | Wholesale & retail | 2016 |
| Ojgb Liquor Limited | Financial services | 2025 |
| Old Millhillians Club Land and Investments Limited | Real estate | 1942 |
| One Biggins Limited | Arts & recreation | 2001 |
| Onyx Hair Salon Limited | Other services | 2020 |
| Open Cities Limited | Administrative & support | 2006 |
| Optalitix Limited | Other services | 2013 |
| Optalitix Solutions Limited | Professional & scientific | 2016 |
| Opusego Limited | Professional & scientific | 2012 |
| Orchidbase Limited | Real estate | 1993 |
| Orvantis Group Ltd | Information & communication | 2026 |
| Peb-Wayne Limited | Administrative & support | 2023 |
| Penrhos House Limited | Hospitality | 2014 |
| PIE and Mash Properties Limited | Extraterritorial | 2025 |
| Pilgrim Long & Sons (Maintenance) Limited | Extraterritorial | 1969 |
| Pinkwhistle Ltd | Professional & scientific | 2012 |
| Portfolio Landlords Action Network Limited | Real estate | 2021 |
| Press Advertising | | 2001 |
| Pro Camera Training Ltd | Other services | 2019 |
| Property Investments (1939) Limited | Real estate | 2004 |
| Proscenium Strategies Limited | Other services | 2010 |
| Quick Mobile Tyres Ltd | Wholesale & retail | 2020 |
| R.A.C.P. | | 2001 |
| Rarewell Limited | Information & communication | 1997 |
| Rayforce Construction Limited | Real estate | 2003 |
| Reality Estate Management Ltd | Real estate | 2003 |
| Remet Ferrous Company Ltd | Wholesale & retail | 2017 |
| Resolute Property Management Limited | Real estate | 1978 |
| RHA Media Limited | Other services | 2010 |
| Rhonda Miller Associates Limited | Administrative & support | 2013 |
| Ridgebrick Developments Limited | Construction | 2025 |
| Rinestone Properties Limited | Real estate | 1988 |
| Robb-Josh Limited | Professional & scientific | 2008 |
| Robintherapy Limited | Health & social care | 2017 |
| Rocodent Limited | Professional & scientific | 2011 |
| Rosebud Prime Estates Limited | Real estate | 2026 |
| Rotisserie Revolucion Ltd | Hospitality | 2024 |
| RPK Partners Limited | Wholesale & retail | 2012 |
| Safe Ride Cars Ltd | Other services | 2015 |
| Sampdore Adventures Limited | Other services | 2014 |
| Sangsara Limited | Professional & scientific | 2011 |
| Sant Engineering Limited | Professional & scientific | 1986 |
| Saydim Lifecare Limited | Health & social care | 2025 |
| Scopal Limited | Administrative & support | 2018 |
| Shapcap Ltd | Real estate | 2026 |
| Shaprop Limited | Real estate | 2019 |
| Shortlift Limited | Real estate | 1995 |
| Simmeir Limited | Real estate | 2015 |
| Simon James Investments Limited | Real estate | 2007 |
| Simon Sayer Sound Engineering Limited | Arts & recreation | 2005 |
| Sinsand Limited | Other services | 2003 |
| SL Studio Ltd | Wholesale & retail | 2019 |
| Soundhouse Property Ltd | Real estate | 2019 |
| Space Data (UK) | | 2001 |
| Spencol Funding Limited | Financial services | 2013 |
| ST. John's Wood Leases Limited | Real estate | 1959 |
| Stag Hair Group Ltd | Other services | 2025 |
| Stargate Event | | 2001 |
| Studio Oates Ltd | Arts & recreation | 2019 |
| Surgisol Limited | Other services | 2007 |
| SW Investments Limited | Extraterritorial | 1999 |
| Swanlane Estates Limited | Real estate | 1999 |
| Sweetslice Ltd | Manufacturing | 2018 |
| Switch to Save Limited | Other services | 2025 |