Outbound Fax Caller ID


I have Freepbx distro (10.13.66-17) with the fax pro module.

I have a user that is the target of an inbound route that is a dedicated fax number.

I am trying to set it so that when the user uses the UCP to send a fax it will go out with that caller ID.
It seems to be using the trunk caller ID.

How can I set this? Note: I don’t wan’t this to be global. I would like to give fax numbers to other users that would work the same way for them.

“Fax Phone Number” and “Outgoing Station ID” are set correctly.

Any help would be appreciated!



If it is helpful, when faxing:
One user (linked to a virtual extension) sends the trunk’s caller ID.
Another user (linked to a SIP extension) sends the user’s “work” number (DID that rings the user directly) and not the fax number.

I’m having this same exact issue. I see you posted this 7 months ago, were you able to find a resolution for the problem?

Sorry, I was never was able to solve this.

I always hope that the cover sheet will suffice but I would love to be able to set the caller ID correctly.

I suspect I could give each user a prefix for faxes that would route to specific outbound trunk with the ID set correctly but it’s an ugly solution.

Setting the caller ID on an outgoing call, any outgoing call, revolves around a series of settings and options that are specific to your environment. For example, in more recent versions of FreePBX, you can specify a limitation on the specific extension for a specific outbound route. This gives you the capability to set a Caller ID on the Outbound Route, regardless of the source. This give you a way to set the Caller ID for a group with the return FAX number, for example.

This should work with a UCP extension as well as any other.

Note that some providers “help” you by setting your Caller ID for you, so you need to make sure that you CAN send your own Caller ID (which I think you can).

There are lots of people that have had issues with Caller ID and UCP. Perhaps you might need to review some of those posts, or give us some more detail so we can more easily follow your current process.


Sorry for not being clear enough.

I have a number of users that have separate DIDs for voice and fax.

When calling out on their phones (or web call from UCP) I would like the caller ID to reflect the voice number and when sending a fax from the UCP I would like the caller ID to be that of their fax.

I have not found a way to set a separate route for the voice extension and fax from the UCP (except for asking users to add a prefix to each fax to select a route.

My trunk providers allow me to set the caller ID. (One only allows me to use DIDs that I provision from that but that isn’t a problem in this case.)

I did not find an answer to my specific problem in the posts when I created this one. I of course may have missed those dealing with the issue. If you are aware of any solutions or posts that resolve this question I would appreciate if you could point them out.

If I am not sufficiently answering your questions, please let me know what additional information could be helpful.

Thank you for any guidance you can provide.

This sounds like a multi-tenant application, and we already know that MT apps are exceedingly hard to do and do not scale well with FreePBX. This outbound CID stuff is probably one of the most challenging areas when you have just voice - adding FAX to the mix certainly doesn’t make it easier.

I’m going to admit a little ignorance on this, in that my setups have always used separate FAX extensions as the source for the outbound FAX. I’ve always used mail2fax scripts for my outbound faxing and have never tried to send a FAX from UCP. In spite of that, I assume that the semantics for that connection are only somewhat different than normal Faxing.

The Caller ID set for voice calls from the extensions should all be working correctly so you should be able to do one of the following to extend your current system:

  • Set the CID entry on the extension as you want it set and honor that set CID on the outbound route and trunk. In other words, allow any outbound CID and do not override the CID on the outbound route and trunk. In my setups, I always set the Caller ID on the FAX extension, so this works for my systems.

  • Use the “extension” field in the outbound route (FPBX 13+) to override the extension Caller ID and to choose a different outbound trunk (perhaps). The advantage of this approach is that, if you have different extensions that you want to be associated with very specific extensions (to support multi-tenant, for example), you can control the outbound semantics at the Outbound Route level (thereby limiting the outbound routes for your callers).

The extension “extension” to the outbound route provides a new semantic for routing calls that prefixes used to facilitate. Now, by querying the extension, you can control the outbound call without having to use prefixes. You may be able to use this feature to control your FAX CID.

Another (more involved) approach might be to use a custom outbound context to route the calls based on their source. Once again, this is theoretical for me since I don’t actually have an application for anything like this, but the approach would be to look at the parameters of the call (FAX from UCP, for example) and set the extension or add a prefix (for example) based on something in the outbound calls setup data. This way, you can select the specific outbound route to override the CID to match the one you want. Note that you could also set the Caller ID in a custom outbound context and just send the call out on it’s merry way.