Check an international dialling change against real routes

An international dialling change can affect the digits sent to a carrier without changing what users dial. Confirm both forms before releasing a route.

Write down the transformations

Record the user-entered number, access prefix, national trunk prefix and number submitted to the provider. Use a country code and destination that the provider permits for testing. Check whether the carrier expects E.164 or another documented format.

Test both directions

Choose an approved outbound destination and a return call if possible. Verify the connected destination and presented caller ID in the carrier record. Test one national and one international route to catch prefix rules that overlap. Keep emergency and short-code routes outside a broad international rewrite.

Save the previous dial-plan rule and set a clear rollback condition for misroutes or unexpected charging.

Consult the international dialling codes guide for country-code structure.