| Ergomed plc | |
| Eridani Star System | Hampshire |
| Erion Ltd | Highland |
| Eritahcus Software Ltd | Surrey |
| Erlang Solutions Ltd | |
| ERM International Group Ltd | |
| Erxes Systems | |
| es Consulting | Hampshire |
| ES Tech Group | |
| ESA Digital Ltd | |
| ESC IT Ltd | |
| Escape Studios | |
| Escher Technologies Ltd | Somerset |
| Eserv | |
| Eseye | Surrey |
| ESG Book | |
| ESG Gaming | |
| ESG Global Ltd | Lancashire |
| eShopFitters | South Yorkshire |
| eSideHustles | |
| Eskdale Solutions | Dumfries and Galloway |
| Esker Ltd | Derbyshire |
| Eskia Computers | South Yorkshire |
| Eskimo Intelligent Solutions | |
| Eskimosoup | East Riding of Yorkshire |
| ESOLS Technologies | |
| ESP Diagnostics | |
| ESP Projects | South Yorkshire |
| Especial Effects Company | Kent |
| ESR Electronic Components Ltd | Tyne and Wear |
| ESR Technology | |
| ESRI (UK) Ltd | Buckinghamshire |
| Essen BioTech | |
| Essence Creative Solutions | South Ayrshire |
| essensys plc | Greater London |
| Essentia Analytics Ltd | |
| Essential | Somerset |
| Essential Consulting | |
| Essential Logic Ltd | West Midlands |
| Essential Logic Ltd | |
| Essential Marketer | West Midlands |
| Essex Computers Ltd | Essex |
| Essex Security Services Ltd | Essex |
| Essex SEO Company | Essex |
| Essex Telecom Installations Ltd | Essex |
| Essex Web Designers | Essex |
| Essiem | |
| eStat Solutions | |
| Estate Apps | |
| Estate Apps | |