How to Address a Letter in the UK: Postal Code Layout and More
The United Kingdom postal code format is a combination of letters and digits: an outward code (area and district, 2-4 characters), a space, then an inward code of one digit and two letters. For example, SW1A 1AA. This compact code tells Royal Mail exactly where to deliver your mail, so writing it correctly on the envelope is essential. Every letter you send in the UK or abroad depends on this format for quick, accurate sorting.
Finding the Right Postal Code
Before you address an envelope, you need the recipient's full and correct postal code. Use the Postcode.is postal code search to look up any UK address by postcode or location. Type in the town name or the partial code, and the tool returns the exact outward and inward code. This ensures your mail is directed to the right place from the start.
Laying Out the Envelope
The address on a UK envelope follows a strict order, one element per line, top to bottom. The table below shows the correct layout for mail sent from abroad (the country line is omitted for domestic mail). Write every line in capital letters, with no punctuation except the space in the postal code.
| Line | What goes on it |
|---|---|
| Line 1 | [recipient name] |
| Line 2 | [street and house number] |
| Line 3 | [TOWN] (in capitals) |
| Line 4 | SW1A 1AA (in capitals) |
| Line 5 | UNITED KINGDOM (in capitals, for international mail only) |
Common mistakes include putting the town on the same line as the street, writing the postal code in lower case, or forgetting the space between the outward and inward parts. For full official guidance on every detail, consult the Royal Mail official addressing guide.
Structuring the Letter
Once the envelope is addressed, focus on the letter itself. A well-structured letter includes: your sender address (on the envelope or in the top-right corner of the letter), the date and place, a greeting, a clear first sentence stating the purpose, a body with the main message, a closing formula, and your signature with printed name. Keep the language polite and direct. For example:
[Sender Address]
[Date]
Dear [Name],
I am writing to [state purpose clearly].
...
Yours sincerely,
[Signature]
[Printed Name]
To draft the letter quickly, use the askai.free AI chat to generate a first version based on your key points, then edit it yourself for tone and accuracy. After writing, run the text through the askai.free grammar checker to catch typos and awkward phrasing. To ensure the letter stays concise — not too short, not overly long — check the length with the wordcounttool.com word and character counter. Aim for a natural length that covers your message without rambling.
Checklist Before Posting
- Is the recipient's name on the first line, spelled correctly?
- Is the street and house number clear and complete?
- Is the town in capital letters, and is it the correct town for the postal code?
- Is the postal code in the correct format (e.g., SW1A 1AA) and written in capitals with a space?
- Have you omitted any unnecessary punctuation or extra lines?
- For international mail, is UNITED KINGDOM in capitals on the last line?
- Is the sender address on the envelope in case the letter needs returning?
- Have you proofread the letter itself for spelling and grammar?
For letters crossing borders, the Universal Postal Union international postal addressing standards provide additional rules to ensure your mail reaches any country reliably. Follow these guidelines, and your letter will arrive correctly addressed and ready to be opened.