An address you type once, and a tax ID field that knows your country
Activation asks for up to two addresses: your business, and the person signing. That is five fields each, typed by hand, in a form where a wrong postal code costs you a verification round trip. It now takes a few characters.
Type three letters, pick a line
Start typing a street in any of those address fields and suggestions appear under it. Pick one and the rest of the address fills itself in: the second line, the city, the state or region, the postal code. Nothing else on the form moves, and every filled field stays editable, because a suggestion is a starting point and not a verdict.
In our own fields, not in a box from someone else
The suggestions are drawn in our own list, styled like the rest of the form, and they answer to the keyboard the way the rest of the form does: arrow keys to move, Enter to choose, Escape to close. We ask the address service for the pieces of the address and we place them ourselves. This matters for a reason beyond looks: nothing you type in that field is handed to a third party's widget along with the rest of your page.
It follows the country you are filling in
Suggestions are restricted to the country selected on the form, so a French company gets French streets. And the address is written the way the country writes it: the number after the street in Germany, before it in the United States. When a country writes its regions as codes, as the United States does, the code goes in; when it writes them as names, the name goes in. Otherwise your region field would fill with a value its own list does not contain.
A tax ID field that knows its own shape
The tax ID field now knows the form your country uses. It shows you the shape before you type, it groups the digits as you go, and it tells you when the number is the wrong length instead of letting the activation fail later.
If the address service is unavailable
The fields stay ordinary text fields and the form works exactly as it did. A missing suggestion never blocks an activation.