I just had an issue with a client who needed 911 and it didn't work even though I thought I had the system configured correctly. I had 911 set as the emergency number. I also had on the outbound rules the Emergency 911 rule modified to prepend a prefix number required by our provider when using IP based authentication (this happened to be Flowroute). They tried dialing 911 but it would fail. Looking at the activity log showed the prefix wasn't being applied. Once I deleted the emergency number from PBX settings, 911 worked perfectly. This should be noted for anyone using a provider or authentication method that requires prefixes. Luckily they had their cell phones nearby and were able to use them instead, and it's partially my fault for not testing it when I set it all up. 3CX - Please add the option to modify the dialed number on emergency numbers as well since this can be very confusing since I didn't think it would completely override outbound call rules. (It does say "When dialled, this number will ignore outbound in office or out of office rules" but my assumption was that this only bypassed the permission blocking outbound calls outside office hours. Just thought I'd give everyone a heads-up just in case you have a similar issue.