Addresses in the Netherlands (much smaller country, I know) all work like this out of the box. People write their return addresses on envelopes that way too, like: 1234AB,56 (where 1234AB is a postal code for up to 15 or so addresses, and 56 is the house number)
I once tested the UK system like that by sending an envelope to myself with just house number and postcode. It worked perfectly, yet convention remains to laboriously write redundant information every time.
The Irish are even better: https://www.irishtimes.com/news/ireland/irish-news/donegal-p...
Recipient name, Street address + number, Postcode doesn't sound that laborously redundant, unless your conventions have something more. Gives a larger area where the mail should go, a precise area where your mail should go (that you can compare to the larger area for mismatches) and who should be able to open the mail.
the redundancy improves reliability. Ink runs, mail gets wet, some small degree ambiguity will likely always exist, etc
Well bully for you. For those of us who live in flats it's not so simple. If you were to put e.g. flat 8 and my postcode there are about 4 or 5 choices so you're probably not going to get your mail.
That's not the same, the system Japan is launching is a code for your address that doesn't change even if you move. It's not a direct mapping to a physical address, it's a DB where you can change which code points to what address.
Anyway, Japan has about 50 prefectures, I don't think any one of them being bigger than the Netherlands (maybe Hokkaido) so they could have a similar system by adding 2 digits at the beginning of the code.
Theoretically, you can just print a DPBC and a name on a USPS delivered mail, and it’ll get delivered. The DPBC has the ZIP+4, and delivery point encoded. The delivery point is the actual mailbox used (some addresses have multiple delivery points, such as apartments).