| Invoiceberry Ltd | |
| Invoit Technologies | |
| Invoke Capital | Greater London |
| Invoked | |
| Involve Visual Collaboration Ltd | Cheshire |
| Invosys Ltd | |
| Invotec Solutions Ltd | |
| Invotyx | |
| invoX Pharma Ltd | |
| Invu Services Ltd | Northamptonshire |
| Inzite Ltd | |
| Inzura Ltd | |
| IO Studios Ltd | |
| IOM Institute of Occupational Medicine and IOM Consulting Ltd | |
| IOM Web Design | Isle of Man |
| iOmart | Glasgow |
| ION Systems | Berkshire |
| IONATE Ltd | |
| Ionburst Ltd | |
| ionCube Ltd | Kent |
| IONETIC | |
| IONIC Recruitment | |
| Iontas | |
| Ionx Solutions, LLP | Aberdeenshire |
| iOra Software Ltd | Hampshire |
| IOS Ltd | Greater London |
| iosBio | |
| Iosoft Ltd | Cambridgeshire |
| IoT Directory | |
| IoT Global Network | |
| IoT Now | |
| IoT Security Foundation | |
| IoT Tribe | |
| iotaSciences | Oxfordshire |
| IOTech Systems Ltd | |
| Iovox | |
| IP Cortex Ltd | Buckinghamshire |
| IP Integration Ltd | Berkshire |
| IP Networks (Europe) Ltd | |
| IP Office Ltd | Devon |
| IP Websites | |
| iPad Repair Manchester | |
| iPad Repair Newcastle | |
| iPad Repair Sheffield | |
| iPad Service Leeds | |
| iPayments | |
| IPChitChat | South Yorkshire |
| ipebble Ltd | Merseyside |
| iPhone Repair Leeds | |
| iPhone Repair Newcastle | |