| Yellowphin Ltd | Lancashire |
| Yellowstone | Bedfordshire |
| Yellowstone Biosciences | |
| Yeovil Circuits Ltd | Somerset |
| Yepic AI Ltd | |
| Yes Computers & IT | West Midlands |
| Yes Creative | Hampshire |
| Yes We Do Websites | |
| YesNo | |
| Yetiserve Computer Services | Cornwall |
| YFM Private Equity Ltd | |
| Yfood | Greater London |
| YLD Ltd | |
| YNH Ltd | Lancashire |
| Yo Telecom Ltd | |
| Yo Wireless Global Ltd | |
| Yobitel Communications Ltd | East Sussex |
| Yodel Delivery Network Ltd | |
| Yodel Mobile | |
| Yogi Communications | |
| Yolkk Ltd | |
| Yonder Consulting Ltd | |
| Yondr Group | |
| YoNET | Kent |
| Yoomee | South Yorkshire |
| Yoozoom | |
| York AV Ltd | North Yorkshire |
| York Bioanalytical Solutions | |
| York Data Services | |
| York Interweb | North Yorkshire |
| York IT Services (UK) Ltd | North Yorkshire |
| York St John University | |
| York UK Hosting Ltd | West Midlands |
| Yorkshire Mac User Group | West Yorkshire |
| Yorkshire Payments | |
| Yorkshire Software | |
| Yorkswebsites.co.uk | |
| Yorktech Solutions | |
| Yorsipp Ltd | |
| Yosh.AI Ltd | Greater London |
| Yoshki | |
| Yospace Technologies Ltd | |
| Yoti | Greater London |
| Yotta | Warwickshire |
| Yotta Solutions Ltd | |
| You Capital | |
| YOU Systems | Cambridgeshire |
| Youmanage HR Ltd | Stirling |
| Young Enterprise Scotland | |
| YouNick | |