| Peak Development Ltd | Hampshire |
| Peak District SEO Ltd | |
| Peak Electronic Design Ltd | Derbyshire |
| Peak Software Ltd | |
| Pearl Lemon Games | |
| Pearl Lemon Group | |
| Pearl Lemon Web Pearl Lemon Ltd | |
| Pearson | Greater London |
| Pearson Treehouse Ltd | Northamptonshire |
| PeaSoup | Surrey |
| Pebble | |
| Pebble Beach Systems Ltd | Surrey |
| Pebble Biotechnology Laboratories | |
| Pebble Ltd | |
| PEC Designs | Greater Manchester |
| Pecometer Software Ltd | |
| Pedal | Greater London |
| Pedalo Ltd | |
| Pedro | |
| Peevish Web Design | Greater Manchester |
| Pegasus IT Consultancy | |
| Pegco Ltd | |
| Pelago | |
| Pelican AI | |
| Pelican Design Consultants | Highland |
| Pelion | |
| Pembroke VCT | |
| Pen Mobile Solutions Ltd | Somerset |
| Pen Test Partners, LLP | |
| Pencil AI Ltd | |
| Pencil Biosciences Ltd | |
| Pencil Biosciences Ltd | |
| Pencil Studio Ltd | |
| Penfriend Ltd | |
| Penguin Internet Ltd | Cardiff |
| Peninsula Group | North Yorkshire |
| Pennine | Greater Manchester |
| Pennine Automation Spares Ltd | West Yorkshire |
| Penny Lane Computers | Suffolk |
| Penridge Multi-Media | South Yorkshire |
| Penta Consulting Ltd | Greater London |
| Pentagon Design | Bridgend |
| Pentagon Electronics Ltd | Wiltshire |
| Pentagon Solutions | Belfast |
| Pentalogic Technology Ltd | Devon |
| Pentasia Ltd | Surrey |
| Pentech Ventures, LLP | Edinburgh |
| Pentland Brands Ltd | |
| Pento Services Ltd | |
| People Counting | |