The technology exists right now to do away with postcodes. I do concede there is a greater problem in the UK because in a place like London, the entire metropolis seems to use “London” as their town/city name, relying on the postcode to route the thing correctly. Here in Australia, “Sydney” is only an area about a mile long by half a mile wide, and although I live close to the geographical centre of the metropolis, the word “Sydney” doesn’t appear in my address anywhere. I’m in the suburb of Belmore, and there are four hundred others in Sydney.
But if the Brits use a county name or abbreviation, the problem of things like the Newtown example is greatly reduced.
I do believe that postcodes will go away. The fact that the likes on insurance companies and banks use them in their databases is just a convenience to those institutions, and I’m sure the Royal Mail would care not one iota about them when it’s looking after its own interests. All those institutions would need to do is update their software and use town and county names instead of postcodes, so that’s not such a big deal.
It’s true that the barcodes or lengthy routing codes used internally do contain the postcode, but that’s just a result of the way it’s evolved, and it’s easier to do it that way. This doesn’t mean there’s anything inherently superior about them, and if they were building a postal system from scratch it would likely be different.
In Australia, every single individual address in the country has a barcode, and the database can be purchased from Australia Post for use by business. The decision was taken here in the 1960s to go with a simple four digit postcode. This was a controversial decision, because at the time the UK and US had more complex codes that could sort finer. The rationale here was that relying on the customer to apply the correct code is a bit dodgy (about 5 or 10 per cent of handwritten mail has a wrong or missing postcode). Anyway, forty years later and our simple codes are no longer a cause for concern because the barcodes enable sorting as finely as is done in countries with long and complex codes. This illustrates how superfluous the codes really are.
In fact, the relatively high percentage of incorrect codes is a strong reason for them to be done away with.
Of course, mail volumes did rise during the 1990s, when everybody was predicting email would kill the post office, but now the email has finally started to bite and the volumes are dropping noticeably, so who knows where we’ll be in ten years?