Yesterday on The Postcode Anywhere blog Guy Mucklow wrote a nice piece called University Challenge. The blog post is about challenges with shared addresses and a remedy at least for addresses in the United Kingdom.
And sure, I also had my challenges with a shared address in the UK as reported in the post Multi-Occupancy.
But I guess the University Challenge is a universal challenge.
The postal formats and available reference data sources are of course very different around. Below is an example from the iDQ™ (instant Data Quality) tool when handling a Danish address with multiple flats. Here the tool continuously display what options is available to make the address unique:
Liliendahl on Data Quality 
Hi Henrik, it’s an interesting point. More often than not we’ve had to rely on ranged data to try and create a premises level addressing service. There are a few national postal service providers who guard their address data jealously – which in our view is pretty narrow minded.
Guy, I agree. Narrow minded indeed. In my work of sourcing reference data postal services therefore are only one of several possibilities. In the above case the reference data is from the government’s property registry.