I love the Google Maps API. Except when using it for UK based addresses. There is a big problem with any app created using the Google Maps API – UK postcodes will NOT be processed, worse still, they return errors.
To give some background on the issue, The Royal Mail own the copywrite for the PAF (Postcode Address File) as its called and charge anyone who wants to access it. You’re probably thinking “but I’ve used postcodes on Google Maps lots of times before….” and you’d be right. The problem emerges as Google refuses (in my opinion rightly so) to pay for its API to access the PAF (see background information), which means that anyone using the Google Maps API for UK purposes is severely handicapped by its limitations from a usability and functionality point of view. What really rubs salt into the wounds is that almost every other major country has there post/zipcode data available freely.
So until this ridiculous situation is fixed, API developers using the Maps API for UK purposes will have plenty of headaches.
Update 9/12/2009: UK Postcode data will finally be free in April 2010, source: http://news.bbc.co.uk/1/hi/technology/8402327.stm