Showing results for 
Search instead for 
Did you mean: 
Walkthrough Wednesdays

Caller ID Displaying "91"

Hi All,

Numbers from people dialing IN are displaying with a "91" prior to the number and is also saving to the directory that way.  Of course, this makes redialing the number form the directory unsuccessful as our dial out prefiex is not 9.  This wasnt always the case, I've just recently had users bring this to my attention.  Can anyone point me in the direction of where I can update the display number format for incoming calls?


Chris Deren
Hall of Fame Master

This depends on few items that you should start out with, what is your phone system, is it CUCM or CME, what version? What protocol is used to control the GW, i.e. MGCP/SIP/H323?

Then there are few places this can be set depending on the above answers.



paolo bevilacqua
Hall of Fame Master

You have a (wrong) translation rule that prefixes 91 unconditionally. It must be written so that it prefixes only if a national calling number is present.

Note: if you are the end user without the necessary experience and certification, it's better to leave this kind of activity to a reputable consultant, or UC certified Cisco partner.

Understood.  I have actually more recently been tasked with handling Call Manager administration and am very new at all of it !.  My system is CUCM 8.5 and we had a lot of help rolling it out.  I was turning to the boards here to be a little more proactive in troubleshooting rather than running to our certified partners for every update/change that comes about.  Of course, before perfomring any changes I'll make sure I'm breaking anything further.

Thanks to everyone for their support and suggestions. I'll post back when I get it resolved.


You might check the Service Parameters for the CM service (make sure you click the Advanced button).  You'll see the following that might be populated in the "Clusterwide Parameters (Device - Phone)" section:

- Incoming Calling Party National Number Prefix - Phone

- Incoming Calling Party International Number Prefix - Phone

I've seen a lot of people add 91 in there for dialing US national for example if the telco is providing 10 digit caller ID.  It may  be prefix digits on the gateways or as mentioned above, a translation pattern on either the CUCM or gateway iteself.  Let me know if this helps.


Content for Community-Ad

Spotlight Awards 2021