We are testing the new WhatsApp feature that comes in version 6.3
The problem is that the messages are received in the international E.164 format and it doesn’t identify the customers’ phone numbers to us.
Because the customer’s phone number is stored in zammad in local format (without country code).
It might be possible to add in the WhatsApp setup wizard, a setting of a country code (or automatic identification), then messages received with this country code will be replaced by 0 instead of a country code.
Zammad has no functionality to force phone numbers into a specific format. It technically (basically) does not care in any way regarding the format you provide.
If you want the WhatsApp Channel to store these numbers in a specific format, this would mean a feature request as it’s currently working as designed: