Connecting Vapi to Your Phone Number
Vapi is the shortest setup of all the built-in profiles: copy your Assistant ID out of the Vapi dashboard, paste it into Click2Call, assign your number. There is nothing to configure at the Vapi end.
Last reviewed: September 2026
At a glance
- Mandatory Click2Call field
- VAPI Assistant ID — the assistant's UUID
- Where Click2Call sends calls
- sip:<assistant_id>@sip.vapi.ai:5060
- Authentication
- None required — Vapi's hosted SIP endpoint does not use registration
- Number format
- +E.164, set automatically
- Code required
- No for call routing; only if you add custom tools to the assistant
- Provider documentation
- Vapi SIP introduction
Connecting Vapi, Step by Step
Build the assistant in Vapi
In the Vapi dashboard, create the assistant that should answer the phone — prompt, voice, model and any tools it needs.
Copy the Assistant ID
Open the assistant and copy its ID. It is a UUID, shown alongside the assistant in the dashboard and also returned by the GET /assistant API endpoint.
This is the only value Click2Call needs. Vapi identifies the assistant from the user part of the SIP address, so there is no separate phone-number import step at their end and no SIP credentials to exchange.
Create the profile in Click2Call
In the Click2Call portal open Voice → Profiles and set Connection Type to VAPI AI Integration.
Paste the Assistant ID into the VAPI Assistant ID field. It is mandatory — the profile will not save without it. Click2Call then builds the route for you, shown under the field as sip:<assistant_id>@sip.vapi.ai:5060, and sets the number format to +E.164.
Assign your number, then check the time zone
Open Voice → Line Manager and set the Profile column for your number to the profile you just created.
The Default profile applies to every line with no profile assigned, and new numbers land on it automatically — a number left on Default will ignore everything you just configured. While you are in the profile, set the Time Zone to where the business operates: business hours, after-hours routing and queue schedules all read it.
Test the call
Ring the number from a mobile. The assistant should answer, and the call should appear in the Vapi call log.
Troubleshooting
The provider replies 407 Proxy Authentication Required
The provider is challenging our INVITE for a username and password, which means our signalling address is not on their allowlist. Click2Call cannot answer that challenge on an outbound call, so the fix is always at the provider end — allowlist 103.212.52.19 rather than issuing credentials. While this is happening, callers hear “the number you have called is not available from this service”.
The profile will not save
The VAPI Assistant ID field is empty or the value is not a valid assistant UUID. Copy it from the Vapi dashboard rather than typing it.
The call connects but Vapi rejects it
Usually the Assistant ID belongs to a deleted assistant, or it was pasted with surrounding whitespace. Re-copy it and save the profile again.
Calls go to Click2Call voicemail instead
The number is still on the Default profile rather than the provider profile, so the call never leaves for the provider at all. Check the Profile column in Line Manager.
You need calls to terminate in the EU
The built-in profile uses the US host sip.vapi.ai. Vapi also runs sip.eu.vapi.ai. Contact support and we will set up a custom SIP route rather than the built-in profile.
Frequently Asked Questions
Where is my Assistant ID?
In the Vapi dashboard, opened against the assistant — it is a UUID. The GET /assistant endpoint returns it too.
Do I need to write code?
Not for routing. The assistant is dashboard-configured; code is only needed if you want custom tools. Compare with OpenAI and xAI, where a webhook is mandatory.
Do I have to buy a number from Vapi?
No. Vapi does not sell Australian geographic numbers, so bringing a Click2Call number is normally the only way to put a Vapi assistant on a local landline or a 1300 number.
Are calls still recorded and transcribed?
Yes, provided Recording Enabled is ticked on the profile. Recording, transcription, summaries and sentiment all work as normal on the Click2Call side, stored in Australia and New Zealand. See AI voice tools.
Related Guides
Still need help?
Our Australian support team is available to assist you.