Address validation using Google Maps API

Question

I have a task to validate addresses entered into a system I am currently creating. The system requires that address entered are validated against a valid data source. In the

Answer 1

I am both a web developer and a former employee of one of the companies you mentioned. I completely understand where you're coming from. Verifying addresses seems like a simple problem to tackle, but it's very much an iceberg. I suppose one workaround to the legal constraints of the Google or Yahoo! Maps APIs is to request your users verify their addresses on a map. If I were in your shoes, though, I wouldn't go that route.

The reason address verification services are so expensive is that they require licenses and ongoing relationships with grumpy, bureaucratic postal authorities (including the Royal Mail). Unfortunately, postal authorities are the best (and often the only) sources of data against which to verify addresses, so there really isn't any other way to go about it. The bottom line is you need to weigh the cost of bad addresses (usually a question of mail volume) against the cost of the software to verify them. Irish postal data is even more rubbish than Irish postal formats (which frequently omit building numbers), so there's little you can do about those addresses.

Answer 2

Another option is YADDRESS.

Answer 3

The answer probably depends how critical it is for you to receive support and possible customization for this service.

Google can certainly do this. Look into their XML and Geocoding API's. You should be able to craft an XML message asking Google to return Map coordinates for a given address. If the address is not found (invalid), you will receive an appropriate response. Here's a useful page: http://code.google.com/apis/maps/documentation/services.html#XML_Requests

Note that Google's aim in providing the Maps API is to plot addresses on actual maps. While you can certainly use the data for other purposes, you are at the mercy of Google should one of their maps not exactly correspond to your legal or commercial address validation needs. If you paid for one of the services you mentioned, you would likely be able to receive support should certain addresses not resolve the way you expect them to.

In other words, you get what you pay for ;) . If you have the time, though, why not try implementing a Google-based solution then going from there? The API looks pretty slick, and it's free, after all.

Answer 4

A great blog describing 14 address finders: https://www.conversion-uplift.co.uk/free-address-lookup-tools/

Many address autocomplete services, including Google's Places API, appears to offer international address support but it has limited accuracy.

For example, New Zealand address and geolocation data are free to download from Land Information New Zealand (LINZ). When a user search for an address such as 76 Francis St Hauraki from Google or Address Doctor, a positive match is returned. The land parcel was matched but not the postal/delivery address, which is either 76A or 76B. The problem is amplified with apartments and units on a single land parcel.

For 100% accuracy, use a country-specific address finder instead such as https://www.addy.co.nz for NZ address autocomplete.