Routing incoming calls to a SIP URI is an advanced feature. 

The SIP URI field allows you to route incoming calls to another SIP provider or service reachable over the internet using a SIP address. If you just want to route incoming calls to your registered SIP phone or PBX, leave this field blank.

The SIP provider or service will publish a scheme for accepting calls by SIP URI. Follow their example to specify the URI on your dashboard at For example, the SIP provider CallCentric states that you can receive calls to your CallCentric account using a SIP URI of

There are public SIP URIs that you can use for testing. Try entering to hear music when you call your Google Voice number.