Verifying an address matches its stated postal code before checkout
A mismatched postal code and city on an order form looks like a small typo until it turns into a delivery sent to the wrong part of the country entirely.
Verifying a business address for a directory listing
Anyone can type an address into a submission form, and not every address typed in is real. A local business directory allowing self-service listing submissions found this out the hard way, fielding complaints from users who had driven to a listed address and found nothing there, sometimes because of an honest typo and occasionally because of a listing submitted in bad faith to game search rankings with a fake local presence.
The directory added a verification step before any submitted listing went live. The submitted address went to /v1/forward, which attempts a match and reports how confidently it resolved, distinguishing a clean match from one that only partially resolved or did not resolve at all. Separately, the postal code entered on the form was checked against /v1/postcode to confirm it corresponded to the city and region also entered on the form, catching the specific and surprisingly common case where a submitter had copied a postal code from a different location entirely, whether by mistake or on purpose.
Submissions that failed either check did not get an automatic rejection, since a poor match is not the same as a fake address, plenty of legitimate businesses have addresses that resolve imperfectly because of new construction or an unusual rural location. Instead, flagged submissions moved to a manual review queue, where a staff member gave them a quick look before publishing, rather than every single submission needing that same manual attention regardless of how clean it was.
This changed the economics of the review process entirely. Before the check, every submission needed a human look, since there was no way to tell which ones were suspicious without checking each one by hand. After it, the overwhelming majority of submissions, the ones that matched cleanly and had a postal code consistent with the entered city, published automatically, and staff time went specifically to the smaller number that needed it, the ones flagged by the verification step itself.
The directory was explicit internally about the limits of this approach. A clean geocoding match confirms an address is well-formed and geographically real. It does not confirm that a business actually operates there, that the business name is accurate, or that the listing isn't otherwise misleading in ways that have nothing to do with the address field. The verification step handled exactly one part of the trust problem, the part about whether the location itself exists and is described correctly, and the directory kept its other moderation practices in place for everything else.
Volume tracked submission volume directly, a modest and predictable number for a regional directory, well inside the free daily allowance included with the key for most months. The change paid for itself many times over in reduced staff review time alone, without even accounting for the reputational cost of a directory known for publishing addresses that lead nowhere.
Documentation for both endpoints, including how match confidence is represented, is at /docs/forward-geocoding/ and /docs/postal-code-lookup/.