Country rules are not interchangeable
A validation rule that works for US ZIP codes can reject Singapore, Canada, Malta, France, Panama, or Bangladesh addresses. Test country-specific patterns, optional region fields, and local phone formatting together.
Prioritize countries with live signals
Start with countries already appearing in analytics or Search Console, then expand once those pages begin ranking. Singapore, Canada, United States, Australia, France, Mexico, Japan, Panama, Malta, Greece, and Bangladesh are good current targets.