Trace an international call that fails or reaches the wrong number

Start with the exact digits entered by the caller and the digits handed to the carrier. A wrong destination can arise before the carrier sees the call.

Follow the number through each rule

Record the dialled string, matched route, prefixes removed or added, final called number and outbound trunk. Preserve the relevant SIP Request-URI and To header, plus the provider’s response and call reference. Redact personal numbers in shared copies while keeping enough digits to explain the transformation.

Separate routing from permission

If the final number is malformed, correct the rewrite. If it is well formed but rejected, check the provider’s international permissions, destination restrictions and account status. A 4xx response alone does not prove the country code is wrong.

Compare with a successful call through the same route and ask the carrier to confirm the rejected digits when needed.

Use the international dialling codes reference to verify the intended number form.