| Nth | Norfolk |
| Nth Exception | |
| NTP Server | West Midlands |
| Nu Creative | |
| NU iSolutions Ltd | |
| Nu Quantum | |
| Nu Quantum Ltd | |
| Nublue Ltd | Lancashire |
| NuCana | |
| Nuclecode | |
| Nucleome Therapeutics Ltd | |
| Nuclera Nucleics Ltd | |
| Nucleus Financial Platforms Ltd | |
| Nudge Reality Ltd | |
| Nuformix | |
| Nugon | |
| Nulynks | |
| Number One Systems | Gloucestershire |
| Number9Dream.com | Berkshire |
| NumberEight Technologies Ltd | |
| NumberGym Software Ltd | Hertfordshire |
| Numedicus | |
| Numeriq Ltd | Edinburgh |
| Numerus Ltd | |
| Numiko | |
| NunaBio Ltd | |
| Nuom Health | |
| NurseBuddy | |
| Nurture Ventures Ltd | |
| Nurtured Solutions | |
| Nutcracker Design & Marketing Ltd | |
| Nutmeg Saving and Investment Ltd | |
| Nutshell Software Ltd | |
| Nuttersons | |
| Nuttersons | |
| Nuttifox | |
| NuttyGeek Technologies | Nottinghamshire |
| Nuvalaw | |
| Nuvem9 | |
| Nuvola Ltd | |
| Nuvomedia | Gloucestershire |
| Nuvotech Ltd | |
| Nviron | Cheshire |
| Nvisage Ltd | East Sussex |
| NVT Group | North Lanarkshire |
| NW Design | Greater Manchester |
| NW PharmaTech Ltd | |
| NW Security Group Ltd | Merseyside |
| NWK Media | East Sussex |
| Nxera | |