You’ve probably seen me rant about the postcode database before. The entry for my little cottage is wrong, and as many UK companies and bureaucracies will only allow you to register addresses that exist in the database much of my mail ends up going to my landlord’s house instead.

But this post is not about my address, it is about other people’s. Because this is the time of year when you send out rather more mail than usual, and that means you may well need to find out someone’s postcode, armed only with their street address.

I tried to do that for someone this morning. It was no surprise when the Post Office website lookup facility could not find the address is question. There are a few other web sites that claim to do postcode lookups. I think I tried three in all. Every one of them gave software errors.

It isn’t like the address in question is hard to find. Google maps has no problem with it. It even gives 4 of the 6 characters of the postcode. But Google isn’t allowed to display the full postcode because the Post Office makes money from selling the database.

So, what is one to do? Actually there is a cunning workaround. I signed into Amazon UK. (Other UK-based retailers may work, but Amazon is somewhere I happen to have an account.) I tried to set up a delivery address using the data I had. Sure enough, Amazon came back with the required postcode. Job done.

So, my question is, given that they both use the same official database, how come Amazon could find the address I was looking for, but the Post Office’s own web site could not?