| Nasstar | Shropshire |
| Nathan Cope | |
| Nathan Stone Database Design Ltd | Suffolk |
| National Aerospace Technology Exploitation Programme | |
| National Centre for Research Methods | |
| National Cyber Security Centre | Greater London |
| National Grid ESO | |
| National Institute for Health and Care Research | |
| National Manufacturing Institute Scotland | |
| National Microelectronics Institute | |
| National Space Centre | |
| Native Legacy | |
| Native System Ltd | West Midlands |
| Native Teams Ltd | |
| NATROX Wound Care | |
| Natural Agency Ltd | |
| Natural HR Ltd | West Midlands |
| Natural Integration Ltd | Bristol |
| Natural Ranks | |
| Naturbeads Ltd | |
| Nature Metrics | |
| NatWest Group | |
| NatWest International | |
| Nauta Capital | |
| Nautilus Marketing | Greater Manchester |
| Nav Info Systems | |
| Navaho | Hampshire |
| Navarino | |
| Navartis | |
| Navenio Ltd | |
| Navigator Systems Ltd | Bristol |
| Navtech Software | Hampshire |
| Nayms | |
| NBM Distribution Ltd | Hertfordshire |
| NC Training Services Ltd | |
| Ncam Technologies | |
| NCG CAM Solutions Ltd | Cambridgeshire |
| NCIMB Ltd | |
| NCLE | |
| NCM Fund & Depositary Services | |
| NCN Systems Ltd | Bedfordshire |
| NCompass Ltd | |
| NCS Support Services Ltd | Lancashire |
| NCTech Ltd | |
| NCube | |
| NDC | |
| NDC London | |
| NDL Software Ltd | West Yorkshire |
| NDP Studio | |
| nDreams | |