How to write a UK address correctly: the order of the lines, what belongs on each one, when the county is needed, and worked examples for England, Scotland, Wales and Northern Ireland. The layout follows the Royal Mail Address Management Guide, the convention known as "Clear Addressing".
A UK address runs from the most specific thing to the least: the property, then the street, then the town, then the postcode. Royal Mail sets the layout out in its Address Management Guide, the convention usually called "Clear Addressing". Getting the order right matters more than getting every optional line present — a correctly ordered address with no county will be delivered; a jumbled one may not.
| Line | Role | Required |
|---|---|---|
| Louise Hall | Recipient | Optional |
| 34 New Place | Number and thoroughfare | Required |
| Estover | Dependent locality | Optional |
| PLYMOUTH | Post town (capitals) | Required |
| Devon | County (Ceremonial county) | Optional |
| PL6 7BP | Postcode | Required |
Three rules do most of the work. The building number never gets a line of its own — it sits at the start of the thoroughfare line. The post town is written in capitals. The postcode goes last, on its own line, and is the only part of the address the sorting machinery genuinely needs.
Each example below is generated from the same registry the generator uses, so the postcode district genuinely belongs to the post town shown and the county is the right kind for that country. The buildings and streets are fictional — these are format demonstrations, not real delivery points.
A numbered property with a dependent locality. The locality sits between the street and the post town, and is only used where it is needed to identify the address.
34 New PlaceThe common shape: number and street on one line, then the post town. In Scotland the county line is a council area.
39 Lime GroveWelsh addresses follow the same layout. The county here is a preserved county, used for addressing rather than local government.
117 Primrose CrescentA named building with no number — common in rural addresses. The building name takes its own line above the street. Northern Ireland uses the BT postcode area throughout, and traditional counties.
Meadow ViewNotice what changes and what does not. The line order is identical in all four. What varies is which optional lines appear, and what kind of administrative area the county line names: a ceremonial county in England, a council area in Scotland, a preserved county in Wales, and a traditional county in Northern Ireland.
Almost never, for delivery. Royal Mail dropped the county requirement in 1996 once postcodes were universal: the post town and postcode locate the address on their own, and mail addressed without a county is delivered normally. The line survives because forms and databases expect it, and because people are used to writing it.
That has a practical consequence when you build software. If your form makes county mandatory you will reject valid addresses, and if you validate the county against the post town you will reject correct pairings — the county someone writes is often the historic one rather than the current administrative area, and both are in common use. Store it if you collect it; do not gate on it.
A form built for US addresses will usually reject or mangle UK ones, because the two systems disagree about structure and not just vocabulary. These are the differences that actually cause bugs.
| Element | United Kingdom | United States |
|---|---|---|
| Sub-building | Flat 3 on its own line, above the street | Apt 4 appended to the street line |
| Building identifier | Number or a name; a name alone is valid | Street number, effectively always numeric |
| Street line | Number then street, no direction: 34 New Place | Number, direction, street: 123 N Main St |
| Locality | Dependent locality, optional and rare | No direct equivalent |
| Town line | Post town in capitals, a sorting designation | City, generally the physical city |
| Administrative area | County, optional since 1996 | State, mandatory two-letter code |
| Postal code | Postcode: 5–7 characters with a space, last line | ZIP: 5 digits, on the city/state line |
| Precision | Postcode plus number identifies one property | Full street address required |
The quickest way to find these assumptions in your own code is to put well-formed UK addresses through it and see what it rejects. A field sized for a five-character postal code, a numeric-only house number, or a mandatory two-letter state will each fail on valid UK input.
From top to bottom: recipient, organisation, sub-building, building name, building number and street on one line, dependent locality, post town in capitals, county (optional), and the postcode last on its own line. Omit any line that does not apply — most addresses use only the street line, post town and postcode.
Yes — the worked examples above show one for each of England, Scotland, Wales and Northern Ireland, each with its lines labelled. A typical English address reads: 34 New Place / Estover / PLYMOUTH / Devon / PL6 7BP, where Estover is the dependent locality and Devon is the optional county.
Royal Mail asks for it, and it is the convention on addressed mail. It is a legibility convention for sorting rather than a strict requirement — an address in mixed case is still delivered. When you store addresses, capitalising the post town on output is a cheap way to match what people expect to see.
No. Royal Mail stopped requiring it in 1996; the post town and postcode are sufficient to deliver. Many forms still ask for it, so include it where a form requires it, but never make it mandatory in software you write, and do not validate it against the post town — historic and administrative counties are both in everyday use.
Last, on its own line, below the post town and any county. Write it in capitals with a single space between the outward and inward halves, as in SW1A 1AA. Some validators are sensitive to that space, so normalising it on input is worth doing.
Five to seven characters in two halves separated by a space, such as M1 1AE, B33 8TH or EC1A 1BB. The outward code before the space identifies the area and district; the inward code after it is always one digit followed by two letters. Six formats are valid and certain letters are excluded at each position — the postcode generator page covers the format in full.
Usually three or four: the street line, the post town, and the postcode, plus a county or building name where one applies. Forms that insist on five fixed lines force people to pad or truncate. Storing the components separately and assembling the lines on output avoids the problem.
A village or neighbourhood inside a post town’s area, included only where it is needed to identify the address — usually when the same street name occurs more than once in that post town. It sits between the street and the post town. Most UK addresses do not have one, so a form should never require it.
The example addresses on this page are fictional. They demonstrate the format and are not real delivery points.