| Phoenix Trescray | |
| Phone and Laptop Repairs NorthEast | |
| Phone Hospital | Glasgow |
| Phones Ltd | Suffolk |
| PhoneShop UK | |
| Phonexa Ltd | |
| PhoreMost Ltd | |
| Phosys | North Yorkshire |
| Photon Storm | Gloucestershire |
| Photonic Solutions Ltd | |
| Photonics Scotland | |
| Photoweb Design | Cornwall |
| phpList Ltd | |
| PHPology | Greater London |
| Phrasee Ltd | Greater London |
| Phurix Internet Services | Greater Manchester |
| Phuse Media | |
| Phygital Ltd | Surrey |
| PhysicsX Ltd | |
| PhysioMedics | |
| Physiomics plc | |
| Phytoform | Greater London |
| Pi Datametrics | |
| Pi Labs | Greater London |
| Pi Labs (Manager) Ltd | Greater London |
| Pi Logic Ltd | Carmarthenshire |
| pi-top | |
| PiBorg | |
| Picaxe | Somerset |
| Pick and Mix Marketing Solutions Ltd | |
| Pick Protection | |
| Pickards Design & Print Ltd | |
| Pickaweb Ltd | Greater London |
| Pickering Electronics Ltd | Essex |
| Pickle Design | Cornwall |
| Pickle IT | |
| Piclo | |
| Piclo | |
| Pico Services Ltd | |
| Picodeliq Enterprises Ltd | |
| Pictura Bio | |
| PicWish | |
| PieCrust | |
| Piksel | North Yorkshire |
| Pikuma | |
| PillSorted Ltd | |
| Pimberly | |
| Pimlico | |
| Pimloc Ltd | |
| Pin Digital | Staffordshire |