This SOP will show you how to keep original CallerID on 3CX after transferring calls.


1. Go to SIP Trunk -- Choose the SIP Trunk



2. Go to Outbound Parameters



3. Change below field to: 


From : User Part ---- "OriginatorCallerID" Original Caller number will be sent

Remote Party ID - Calling Party : User Part ---- "OriginatorCallerID" Original Caller number will be sent

P-Asserted Identity : User Part ---- "OriginatorCallerID" Original Caller number will be sent

P-Preferred Identity : User Part ---- "OriginatorCallerID" Original Caller number will be sent


4. Click the OK button to asave all changes