What the sorting equipment is actually reading
Postal sorting is largely automated, and the machinery is not reading your address the way a person reads it. It is looking for a shape in a known position: a postcode in the format that country uses, on the line that country puts it on, next to the town name it expects to find beside it, with the destination country given in a form the exporting service recognises. When the shape matches, the item is routed mechanically and nobody looks at it. When it does not, the item drops out of the automated flow and its future depends on somebody having time.
This is why the condition is about form rather than content. Line order matters. Whether the postcode precedes or follows the town matters, and it differs by country. So does whether the country name is written in your language or in the language of the exporting service, and so does an extra line the format does not have, because it pushes everything else out of position. All of it is decided in the seconds you spend typing, and none of it is checked afterwards by anything that will tell you.
The blunt version: most delivery failure is formatting failure. It is not a mystery of the network, it is a decision made at a keyboard by somebody typing an address the way they would type it into a web form with autocomplete behind it. Nothing here has autocomplete behind it.
Where the required shape comes from
One card sits above this one, The listing is one you have actually read, and it supplies the local half of the requirement. Whoever will be writing the label often states what they want and what they cannot use: how many lines they will accept, whether a name is expected, what to leave out. That is not the same as the postal format, and both have to be satisfied at once. The postal service decides what the machine can read. The listing decides what the person writing the label is able to work with.
Beyond that, this card is unusually self contained. It needs no value, no wallet and nothing from stage E. If you want to see how few edges run into it, the How to read a card page explains why a card with one parent and three children behaves like a bottleneck rather than a step.
Three conditions that never get a chance to be true
This is a bottleneck, and it is worth being exact about the mechanism, because two of the three failures are failures of a question never being asked rather than of an answer being wrong.
What you send is encrypted to a key that exists comes after this one for a reason that is purely about order of operations. The thing you encrypt is normally the address block itself. Encryption preserves whatever you give it with perfect fidelity, including the wrongness. Once the block is sealed you have also sealed the mistake, and correcting it means producing and sending a second block, which is the single most common way people end up transmitting the same details twice through different channels.
Somebody can take delivery at that address presupposes that an item reaches that address. A malformed address does not produce a doorstep with nobody at it. It produces an item sitting in a returns pile, or delivered to a similarly named street in a different town, or held at a counter that expects somebody to come and ask for it. The question of whether a person was home never arises, because the parcel and the door never meet.
The name on the parcel fits the door it arrives at fails in the same way and for the same reason. It is a question about the match between a name and a building, and it can only be asked once the item is at the building.
| Cannot hold | The reason it cannot |
|---|---|
| Encrypted to a key that exists | The sealed block contains the malformed text, faithfully preserved |
| Somebody can take delivery | The item never arrives at the door the question is about |
| A name that fits the door | Same reason, one step further along the same chain |
Both parcel cards below this one are the end of their chain. That means a formatting mistake here does not surface as a warning anywhere upstream. It surfaces as an absence at the far end of the map, and by then every other condition on the way has already reported success.
How a mistyped line spends the next stretch of time
You type it the way you type addresses, which is the way your own country writes them. Nothing rejects it. There is no validation, no autocomplete and no red outline, because the field is a plain box and the person at the other end has no way to know what the correct version looks like. It is copied onto a label exactly as given.
Then nothing happens, for a while, and the absence is the only symptom you get. No message arrives to say the address was unreadable, because the party who discovered it is a sorting facility with no idea who you are. Meanwhile the confusion lands in entirely the wrong place. You start doubting whether anything was ever sent, and the other side has a record saying it was. Two people are now arguing about honesty when the actual event was a postcode on the wrong line. That misdirection is the reason this card is on the map at all.
Checking it line by line against the published format
Every postal service publishes the format it wants for inbound mail, including line order, postcode placement and how the country should be written. Find that published format for the destination country and compare it against what you typed, one line at a time, in order.
A pass means every line in your version corresponds to a line in the published format, in the same position, with the postcode in the stated pattern and nothing extra. A fail has a recognisable signature: a line the format does not have, or a postcode written the way your own country writes postcodes, or a country name in a language the exporting service will not be reading. If you cannot locate the published format, treat the condition as false rather than as probably fine.
Only the shape of the lines
It is not advice about where anything should be sent, and this site does not discuss that question anywhere. It is only about the shape of the lines once a destination exists. It is also not the same as Somebody can take delivery at that address, which is about the day and the door rather than about the text.