| Whitespace | |
| Whitewall | |
| Whiz Solutions Ltd | Greater London |
| WHMCS Ltd | Buckinghamshire |
| WhoisTrustee.com Ltd | |
| Wholegrain Digital | |
| WholeLot | |
| WholesGame | |
| WhosOn | Staffordshire |
| WHP Telecoms Ltd | Cheshire |
| Why Research Ltd | |
| Why Think Domains Ltd | Surrey |
| WhySettle | |
| Wi-Manx Ltd | Isle of Man |
| Wibble Web Design Ltd | Belfast |
| WICASTR | |
| Wicked Kippers | |
| Wickham Micro Ltd | |
| Wicks and Wilson | Hampshire |
| Wida Group Ltd | Nottinghamshire |
| Wide Angle Software | Wiltshire |
| Wideopenspace Ltd | |
| Widescope.net | Northumberland |
| Widgit Software | Warwickshire |
| Wieser Software | Cambridgeshire |
| WiFiGear Ltd | |
| WIFIPLUG Ltd | |
| Wigwan Digital Ltd | Glasgow |
| WilconCooke | Greater Manchester |
| Wild Applications | Essex |
| Wild Dog Design | East Sussex |
| Wildanet Ltd | |
| Wildcard Networks | |
| Wildcat Applications Ltd | |
| Wildcat Creative Marketing | |
| Wildcat Solutions | Glasgow |
| Wildesoft.net | |
| Wildish & Co. Ltd | |
| Wildtalk Ltd | North Yorkshire |
| William Dean Consultancy Ltd | Berkshire |
| Williams Commerce | Leicestershire |
| Williamware.com | |
| Willo Technologies Ltd | |
| Willow Ridge Digital | |
| Willow Technology (Isle of Man) Ltd | |
| Wills Services | |
| Wilson Grey | |
| Wimborne Business Systems Ltd | Dorset |
| Win Media | |
| Wincanton's W2 Labs | |