| Name | Region |
|---|---|
| XeBusiness | Greater Manchester |
| Xecutors Ltd | |
| Xelix | |
| Xen Project | |
| Xen Solutions Ltd | Greater London |
| Xen-Tools.org | Cambridgeshire |
| Xencentric Hosting | Greater London |
| Xenogenix Ltd | |
| XEPOS | |
| Xergy Group | |
| XeyoX Interactive | Herefordshire |
| Xgenera | |
| XGS Systems Ltd | Essex |
| Xi8 Media Ltd | Armagh City, Banbridge and Craigavon |
| XiApps | |
| Xiatech | |
| Xigen Ltd | Bedfordshire |
| xilo Ltd | Hampshire |
| Xiros Ltd | |
| Xist2 | Oxfordshire |
| XJTAG | Cambridgeshire |
| XKS Ltd | Denbighshire |
| XL Group | |
| XL Telecom | |
| XLMedia plc | Channel Islands |
| XLR Group Ltd | |
| XLWEB | |
| XMA Ltd | Hertfordshire |
| XML Summer School | Oxfordshire |
| XML-Sitemaps.com | Bedfordshire |
| XMLPrime | Cambridgeshire |
| XMOS | Bristol |
| Xneik | |
| Xonai | |
| Xoomworks Ltd | Greater London |
| XovoTech | |
| Xpand | |
| Xperience | Lisburn and Castlereagh |
| Xperience Plus | |
| Xperteria | |
| XpertRule Software Ltd | Greater Manchester |
| Xperts Web Design | Glasgow |
| Xperts Web Design | |
| XPO IT Services Ltd | Shropshire |
| Xposure Creative | Nottinghamshire |
| XR Digital | |
| XR Games | West Yorkshire |
| XR Therapeutics Ltd | |
| XR Today | |
| xRealityLabs |