Please note that this feature is not available on all systems.
Dial plans allow different telephones or remote access accounts to be in different countries, and each dial as though they were in that country. If your system has been configured for dial plans, you may choose the default dial plan for your customer under the Settings » Customer menu. You may then leave your telephone lines at "Default", or choose the country they are in. If you do not see the appropriate country, please contact your vendor so it can be added.
If you are a reseller, changing your customer's dial plan does not affect your customers. They will still use the system dial plan by default.