Modifying CLID for incoming calls


I did a search for this but nothing helpful showed up.

We have a small Asterisk setup whereby incoming calls are received via our telco’s IAX server. The system is set up to require users to dial ‘9’ for external calls.

My problem is that, when calls are received, the caller ID doesn’t have the ‘9’ prefix, so if you try and redial an external number straight from the missed calls list on the phone, it doesn’t work.

Is there a way to get Asterisk to prefix the incoming caller ID with a ‘9’ when routing the call to one of our internal SIP phones?

Any help with this would be much appreciated.



exten => whatever,1,Set(CALLERID(number)=9${CALLERIDNUM}) should add a 9 to the beginning of the number… use it when a call comes in.


Thanks a lot.