[According to Wikipedia] the aim is to have one post-code per fifteen addresses. Which means that unlike (5 digit) ZIP codes and German Postal codes, UK Postco

[According to Wikipedia] the aim is to have one post-code per fifteen addresses. Which means that unlike (5 digit) ZIP codes and German Postal codes, UK Postcodes are typically pretty useful for navigation - people will often enter a postcode into a Sat-Nav to reach a home or business. However, sometimes this can entirely fail - e.g. for a historic house on a large estate which may have access some hundreds of meters away from the postcode indicated location, and so sometimes you'll see a separate postcode to put into your Sat-Nav !