Redirect inbound calls to trunk not working for withheld numbers


I’m redirecting all inbound calls to a SIP trunk.

In FreePBX ( I achieved this by setting the inbound route destination to a group. The group then has the external phone number set in the extension list. I have one trunk set-up to use our SIP provider.

This all works fine for most calls. However, for people calling with number withheld then they end up going to the group’s “Destination if no answer” option. The logs show the call as having the disposition “busy”.

The SIP provider is configured to allow anonymous calls, and calling their incoming phone number directly with number withheld works fine.

So something in the way that FreePBX is routing the calls with number withheld to the SIP trunk is causing a problem. Either the SIP provider is rejecting it for some reason, or FreePBX thinks it is busy for some reason. However, I have been unable to find out what the problem is.

Does anyone have any suggestions as to what might be causing this issue please?

Thanks in advance for any help.


I can see in the logs that the SIP provider rejected the call:
Got SIP response 603 “Declined”

I’m just assuming that your SIP provider is rejecting these with-held calls.