| Hype London Ltd | |
| Hypeople Studio | |
| Hyper Host | |
| Hyper Luminal Games Ltd | |
| Hyper Pixel Ltd | |
| Hyperbrand | |
| Hyperexponential | |
| HyperFinity | |
| Hypergalaxy Ltd | Leicestershire |
| Hypergroup Ltd | Kent |
| HyperJar Ltd | |
| Hyperneph Software Ltd | |
| Hypersay | |
| Hypertec Ltd | Berkshire |
| Hypervision Surgical Ltd | |
| HYPERVSN | |
| Hypetec | |
| Hypha Discovery Ltd | |
| Hypha Knowledge Integration Ltd | |
| Hypha Media Ltd | |
| HySoft Ltd | |
| Hyve Managed Hosting | East Sussex |
| I-Galaxy Media Ltd | |
| I-Pro Software Ltd | Wiltshire |
| i-Solutions Global Ltd | West Midlands |
| I.C.O.M International Ltd | |
| i.LEVEL Software | |
| I.T. Dev Ltd | Hampshire |
| I.T. Trading UK Ltd | Wiltshire |
| i2 Security Ltd | Oxfordshire |
| i2 SustainIT | |
| i2B | County Durham |
| i2W Ltd | East Sussex |
| i3MEDIA Ltd | Cambridgeshire |
| i4 Product Design Ltd | |
| i6 Group Ltd | |
| IAG Technology Ltd | Buckinghamshire |
| Iain Claridge | Bristol |
| IAM Technology Group Ltd | West Yorkshire |
| Ian Craig | East Sussex |
| Ian Sharpe | Somerset |
| Ian Spencer | |
| Ian Yates | Tyne and Wear |
| IAT Ltd | |
| IATX Ltd | |
| ib3 Ltd | Kent |
| IBC | |
| Ibcos Computers Ltd | Dorset |
| Ibex Internet Ltd | Cumbria |
| IBEX UK Ltd | Surrey |