Use a region-specific address format if almost all your users will be in the same region — 90% or more. When using a region-specific address format, default the “Country” to the appropriate location.

On mobile, this should appear as a one-column layout.

If an address input needs to be as generic as possible to serve a widely international audience, use a one-column layout to display all options.

When possible, use the Google API style of selecting an address. With one field, the user types in the entire address and an autocomplete assists them on finishing the information. If no network connection is available, use the international generic address.