| Rigorous Digital | |
| Rija Media | |
| Rinato Media Ltd | |
| RingPay Ltd | |
| RingStone | |
| Ringtail Software Ltd | |
| Rinicom Ltd | Lancashire |
| Rinky Dinky Ltd | Cardiff |
| Rinri Therapeutics Ltd | |
| Rio ESG Ltd | |
| Riot & Rebel | |
| Ripjar Ltd | Gloucestershire |
| Ripple Foundation C.I.C. Ltd | |
| Ripple Technology Solutions Ltd | |
| Rippleffect Group Ltd | |
| Ripplenet Web Design | Greater London |
| Ripples Design | Devon |
| RISC Group | Conwy |
| Rise Digital Media | |
| Rise Online | |
| Rise Reseach Ltd | |
| Rishvi Ltd | |
| Risilience | |
| Risk Decisions Ltd | Oxfordshire |
| Risk Ledger | |
| Riskfree UK Ltd | Shropshire |
| RiskSmart | |
| RISO UK Ltd | Hertfordshire |
| Rite IT Solutions Ltd | |
| Rittman Mead | East Sussex |
| Riva Money | |
| Rivalry Ltd | |
| Riven Associates Ltd | Surrey |
| River IT Group | |
| Riverbank Computing | Dorset |
| Riverbank IT Management | Oxfordshire |
| Riverlane Ltd | |
| Riverside Automation | South Yorkshire |
| Riverview IT | |
| Riviera Networks Ltd | |
| Rivmedia Digital Services | Norfolk |
| Rixxo Ltd | |
| RJM Digital | East Sussex |
| RJS Consultants | Hertfordshire |
| Rkd Computers | Cheshire |
| RKM Software | |
| RKWO | |
| RL Supplies | Hertfordshire |
| RLS Computer Services | Norfolk |
| RM Education | Oxfordshire |