The main difference is where the phone system runs.
A SIP trunk connects an existing compatible PBX to the telephone network. A hosted PBX moves the call-control platform into a provider-managed environment and gives users access through phones and apps.
Choose SIP trunks when...
- Your existing PBX remains suitable and supported
- You want to retain established call flows and integrations
- Your team can maintain the PBX and its security
Choose a hosted PBX when...
- You want to replace ageing on-site hardware
- Remote users and mobile apps are important
- You prefer the platform and resilience to be managed
Number porting can preserve eligible existing numbers in either approach. Compare our SIP trunks, Hosted 3CX and number porting service.