| F.J.Wibberley(Haulage)Limited | | 1964 |
| Faccenda Farms Limited | Agriculture & fishing | 1982 |
| Faccenda Foods Limited | Manufacturing | 1982 |
| Faccenda Investments Limited | Professional & scientific | 1984 |
| Fastline Group Limited | Wholesale & retail | 2001 |
| FMT Estates Limited | Real estate | 2015 |
| Food Safe Limited | Manufacturing | 2019 |
| Freightroute Limited | Transport & logistics | 1972 |
| Future State Media Ltd | Wholesale & retail | 2014 |
| G J K Electrical Contractors Ltd | Construction | 2021 |
| G S Maddison Limited | Construction | 2003 |
| G.L. Chambers Developments Limited | Construction | 1983 |
| Gardner Creative Limited | Professional & scientific | 2002 |
| Gateway HR and Training Ltd | Professional & scientific | 2006 |
| Geobell Limited | Real estate | 2019 |
| Graham Churchill Plant Limited | Construction | 1986 |
| Groundcare Contracting Ltd | Construction | 2004 |
| H.B. (Audio Visual) Limited | | 1984 |
| H.E.S. Power Tools Limited | | 1975 |
| Haes Cooper and Company Limited | Professional & scientific | 1990 |
| Haillo Design Consultants Limited | | 1985 |
| Haptic Networks Limited | Information & communication | 2004 |
| Harish Thakrar Limited | Professional & scientific | 2005 |
| Harris Family Holdings Limited | Professional & scientific | 1973 |
| Harwoods Surveyors and Estate Agents LLP | | 2014 |
| Henry's Autos Ltd | Wholesale & retail | 2007 |
| Henry's Drylining Limited | Construction | 2005 |
| Hi-Shine Limited | Transport & logistics | 2005 |
| Hickory House Nursery Limited | Education | 2003 |
| Holroyd Consulting Limited | Professional & scientific | 2007 |
| Hootens Farm Ltd | Agriculture & fishing | 2023 |
| Hydro TEC Limited | Professional & scientific | 2007 |
| I S H General Contractors Limited | | 1987 |
| Ican Broadcast Limited | Information & communication | 1998 |
| ID PR and Marketing Limited | Information & communication | 2005 |
| ISE Lodge Community Centre Limited | Arts & recreation | 1991 |
| J & SP Partners Limited | Administrative & support | 2019 |
| J S Typesetting Limited | Administrative & support | 2001 |
| J.G. Clarke (Finedon) Limited | Real estate | 1964 |
| J.K. Electrical (Daventry) Limited | | 1979 |
| Jacklogic Limited | Information & communication | 2007 |
| Jackson Toms Financial Services Limited | Financial services | 2003 |
| Jason Transport Ltd | Transport & logistics | 2005 |
| Jaysim Groundwork & Building Services Limited | Construction | 2006 |
| Jerry Wood Electrical Services Limited | Construction | 2006 |
| JJB Chartered Architects Limited | Professional & scientific | 2005 |
| John Shortland Carpentry Services Limited | Manufacturing | 2003 |
| Johnsons Tax Administration Limited | Public administration | 2024 |
| JON Essam & Co Limited | Professional & scientific | 2001 |
| JON Spencer Technical Drawing Limited | Professional & scientific | 2003 |
| K Irvine Plant (UK) Limited | Administrative & support | 2007 |
| K.M. Packaging Holdings Limited | Professional & scientific | 2007 |
| K.M. Packaging Services Limited | Manufacturing | 1984 |
| Kedian Engineering Limited | Professional & scientific | 2002 |
| Keelings UK Group Limited | Professional & scientific | 1971 |
| Kiloni Ltd | Wholesale & retail | 2005 |
| L. Prescott Ltd | Professional & scientific | 2007 |
| LAN Technology International Limited | Construction | 1989 |
| Leather Consultancy Ltd | Professional & scientific | 2005 |
| Lets Move Homes Limited | Real estate | 1999 |
| Lightning Signs & Embroidery Ltd | Manufacturing | 2018 |
| Linden Barn Ltd | Agriculture & fishing | 2007 |
| Link Hire 4000 Limited | | 1981 |
| Linslade Tyres Limited | Professional & scientific | 1968 |
| M & a Fletcher Limited | Real estate | 1981 |
| M & N Clayton Plumbing & Heating Limited | Construction | 2005 |
| M K Health Care Ltd | Health & social care | 2006 |
| Manacon Associates Limited | | 1977 |
| Manders Construction Limited | Construction | 1982 |
| Mann Property Management & Investment Services Ltd | Real estate | 2024 |
| Marc Wood AE Ltd | Arts & recreation | 2019 |
| Market Shape Limited | Professional & scientific | 1991 |
| Marlec Engineering Company Limited | Manufacturing | 1978 |
| Martin Shelley Drive & TOW Limited | Education | 2007 |
| Master Abrasives Ltd | Manufacturing | 1967 |
| Matthew Wylde Ltd | Construction | 2007 |
| MC Materials Ltd | Professional & scientific | 2006 |
| Merida Associates Limited | Information & communication | 2012 |
| Metcalf Commercial Decorators Limited | Construction | 2001 |
| MH Computech Ltd | Information & communication | 2005 |
| Micro Film Services (Northern) Limited | Professional & scientific | 1957 |
| Midland Stone Centre Ltd | Manufacturing | 2005 |
| Mike Edginton Cars Limited | Wholesale & retail | 1998 |
| Milthorpe Property Investments Limited | Real estate | 2007 |
| Miltons (Wallpapers) Limited | Wholesale & retail | 1948 |
| Mjib (Northants) Ltd | Other services | 2025 |
| Models for Sale Limited | Wholesale & retail | 2003 |
| Morning Star (Northants) Limited | Health & social care | 2005 |
| MRW Transport Limited | Transport & logistics | 2007 |
| MSR Electrical Limited | Construction | 2003 |
| Mustard Spice Ltd | Hospitality | 2021 |
| MV Lites Limited | Other services | 2012 |
| MW Electrical (Midlands) Ltd | Construction | 2007 |
| N E S Build Limited | Construction | 2002 |
| N Hirst Limited | Administrative & support | 2003 |
| Nash Mynard Design Limited | Professional & scientific | 1977 |
| Neurelec Limited | Transport & logistics | 2005 |
| Nightwatch Services Limited | Administrative & support | 2007 |
| Northampton Gilbert & Sullivan Group | Arts & recreation | 1994 |
| Northamptonshire Electrical Wholesalers Ltd | Wholesale & retail | 2010 |