| Inforox | |
| InfoSec Conferences | |
| Infosecurity Magazine | |
| Infoserve Ltd | West Yorkshire |
| InfoSum Ltd | |
| Infotechnics | Aberdeen |
| Infotek Software Ltd | Monmouthshire |
| Infotex | |
| Infotone Imaging Supplies Ltd | North Yorkshire |
| InfoVibes Ltd | |
| Infoworks Ltd | Surrey |
| InfraRed Integrated Systems Ltd | Northamptonshire |
| Infusion Web Services | |
| Ingenica Solutions Ltd | |
| Ingenious App Studios | |
| Ingenious Ideas Ltd | |
| Ingenta | Oxfordshire |
| Ingenuity Digital | |
| Ingenza Ltd | |
| Inhabit | |
| InHand Systems Ltd | South Yorkshire |
| InHealth Ventures | Greater London |
| Inigo Media | Edinburgh |
| Inisoft Ltd | Glasgow |
| Initforthe Ltd | Greater Manchester |
| Initiative2 | Aberdeen |
| Ink Save | Wiltshire |
| Ink Shop | West Midlands |
| Ink Warehouse | Kent |
| Ink2U | Somerset |
| Inkbox | Norfolk |
| Inkcap Design Ltd | Somerset |
| InkFactory.com | Lincolnshire |
| Inkjet Cartridge Shop | Warwickshire |
| inkle Ltd | |
| Inkless Ideas | |
| Inkraider.co.uk | Greater Manchester |
| INKredible UK | County Durham |
| Inktec | Scottish Borders |
| Inktrap | |
| Inkwell Conceptual Design | Mid-Ulster |
| Inline Manual Ltd | |
| Inline Manual Ltd | |
| InLinks UK | |
| inLinx Ltd | |
| INM Infinity Net Media | |
| InMotion Ventures Ltd | West Midlands |
| Innerworks | |
| Innivo Ltd | Monmouthshire |
| Innofactor plc | |