### Answer
It sounds like you're encountering issues with your inbound call setup for an Australian number imported from Twilio to Vapi. A couple of things might be happening here based on the information provided in the documents and similar cases discussed:
1. **Valid JSON Response**: Ensure that your server is sending a valid JSON response. Misconfiguration or incorrect JSON response from your server when Vapi tries to handle the inbound call can lead to issues where the assistant cannot be connected [(1)](
) .
2. **Region Configuration**: There was a case where a user faced issues with Australian and New Zealand numbers, which were resolved by ensuring the numbers were configured to use the United States region in Twilio before importing into Vapi. After import, they rerouted to the original region and copied the webhook URLs [(2)](
) . Although this seems more related to the initial setup, ensuring that your Twilio settings, especially the webhook URL for handling calls, are correctly configured is critical.
3. **Check Phone Number Import**: Make sure the phone number was imported correctly. An incorrect import process might lead to issues where the assistant is not correctly assigned to handle inbound calls. It was mentioned that something could go wrong in the import process, and Vapi expects a POST request, not GET, which might be worth reviewing [(3)](
) .
4. **Review Twilio Configuration**: Double-check your Twilio configuration for the imported number. Ensure that the webhook URLs are correctly set up to point to your Vapi server URL where your assistant is configured to handle calls [(4)](
) .
If you've already che