Saw some answers here which suggest paid services or complicated address validation designs, but it doesn't apply to our specific case.
We have a lead capture form that lets users start typing the address and it autocompletes it for them:
And there's 2 common mistakes which we keep seeing:
1) Missing door number
2) Missing city name (as in the screenshot)
We're looking for a loose address verification which has room for error and that checks if there is a:
a street number and city name in the address
We could do a simple regex to make sure there's numbers in users' input, but if we could do both using Google API that would be great.
P.S: We do display a Google map so we're not breaking their TOS by making API calls to validate the address.
Update:
I was thinking of using JSON like this http://maps.googleapis.com/maps/api/geocode/json?address=45.4993726,%20-73.5653678&sensor=false which is returned by Google maps and does contain street numbers etc. By door number I mean street number (it's under long_name)