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jen729w

Random UK postage fact. Our postcodes are so specific, it's sufficient to write the house number and the postcode.

We sent ourselves a postcard from Spain addressed to:

S_3 _S_ (redacted)

– and it arrived.

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No need for an address in Ireland, a general description of the recipient will do.

https://www.irishpost.com/life-style/irish-postman-somehow-d...

Around 1800 there was a letter addressed "Sromfidevi England". After some head scratching they delivered it to Sir Humphry Davy.

My parents' house shares a postcode with just one other house.

When I was in secondary school, one of my classmates didn't believe a letter would reach me if the envelope had only my name and postcode (no house number or street name), so I gave him a stamp and challenged him to try.

I brought the letter to school a couple of days later.

How broadly true is that[1] in the UK (I’m assuming UK here, and not AUS or NZ or some other anglosphere country)? And is it more true in rural areas vs the city?

1 - a post code resolves to something approximating a single physical address, or at least close enough to reliably allow delivery

Not broadly true in the UK. The median is probably 15 or 20.

I've only ever lived in cities.

A post code is usually a few streets. Precise enough to prpbably figure put the restof the way in a pinch but still a pretty large number of potential addresses.

A post code is usually a few houses, 15 on average according to Royal Mail, so that's usually a single street.

There are exceptions in rural areas, where one post code covers multiple streets.

That is insanely specific. By contrast, my US zip-code covers at least 75 square miles, and that's a conservative estimate.

It is extremely convenient when filling in online forms, giving an address over the phone, or when getting into a non-app taxi.

Web forms and the in-car navigation prompt first for the postcode, then present a list of the full addresses and you pick one.

Over the phone, "W10 6TR" also avoids needing to spell anything, and I encourage you to search Google for it.

There's also some human readable part. The W means West London, people who live in West or South West London will be familiar with some numbers - W10 is Ladbrook Grove. B is Birmingham, BS is Bristol, BT is Belfast etc.

Are you referring to the 5 or 9 digit variant? Presumably not the 11 digit one as that corresponds to your unique address. (It follows that the 9 digit variant corresponds to at most 100 mailboxes.)

I've never tried inputting my 11 digit code in an online form but at least the 9 digit one is readily accepted. In my experience the last 4 will usually be completed for me based on the street address and if it can't find a match it gives me an error.

I didn't even know there was an 11 digit code until now! I was referring to the 5 digit code. 9 digit would be closer, but around here 100 mailboxes (zip+4 would actually be 9999 mailboxes) is still quite a few square miles. If I look out my living room window, I can see maybe 10 houses, and that's with a view that comes from living on top of a hill.

Zip+4 (9 digit) can't ever be more than 100 mailboxes because 11 digit is guaranteed unique. It follows that a 5 digit zip is limited to 1M boxes.

Unless I have a misunderstanding about 11 digit being unique anyway.

It depends. My postcode covers more like 50.

Allegedly the US ZIP code system is similarly precise if you use the extra four digits plus the last two digits of the address number. For example, 89434-8669-35 should be enough to send mail to my favorite bar in town (assuming said bar accepts mail there; can't say I've ever tried).

That's a coffee shop.

Looks like there’s a bar next door.

It's also a bar! And they sell comics and related paraphernalia, hence the name of the place.

It turns out there are only two houses in my zip+4. But I don't have much confidence on my mail reaching me with just that...

Post offices have their own zip codes (usually one higher than the town they're in) and if they have less than 10,000 PO Boxes, ZIP+4 identifies one uniquely.

Singapore is like this - 5 digit numeric postal code in a country where most people live in apartment buildings (HDB's).

As a result, most towers (blocks) have their own post code. Even in complexes with 3 towers sharing a common main level (floors B2 through 3), still have their own postcode.

If you go on website and put your postcode, it will autocomplete the address except for the unit number.

Same in the Netherlands. Postcode and house number is unique and enough to deliver mail. I usually write the return address that way.

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