The URLs for the synchronous and asynchronous frontends are:
| Service | Front | URL |
- Barcelona Association of Surveyors, Technical Architects and Building Engineers (CAATEEB)
- College of Telecommunications Engineers (COIT)
- Association of Notaries of Catalonia / ANCERT (Notarial Certification Agency) – request for electronic copies
- Property Registry
- Commercial Registry
- Official Colleges of Catalonia (DCOC)
- Official College of Architects of Catalonia
| Synchronous | https://serveis3.iop.aoc.cat/siri-proxy/services/Sincron |
| Asynchronous | https://serveis3.iop.aoc.cat/siri-proxy/services/Asyncron |
| Asynchronous-response | https://serveis3.iop.aoc.cat/siri-proxy/services/AsyncronResposta |