Checkout phone number E.164 validation
Key Takeaway
By default, checkout converts phone numbers to E.164 format, so a stored number that looks different from what the buyer typed is expected. If validation fails for an unsupported country code, enable the "CheckoutSkipPhoneValidation" org permission.
B2B Commerce checkout validates the phone numbers that buyers enter. By default, the validation changes the format of a number, which can surprise buyers and developers. The validation can also block checkout for some countries. To troubleshoot these problems, you need to know the cause and the org permission that turns validation off.
What checkout does to phone numbers
By default, checkout phone number validation converts the buyer's input to E.164 format and removes the hyphens and other formatting. So if a stored number looks different from what the buyer typed, that is expected behavior, not a defect in custom code.