How to Address an Envelope in Ireland: Official Guidelines

Sending a letter in Ireland is more straightforward than you might think — once you know the exact order of each line. With the introduction of Eircode in 2015, every residential and business address now has a unique seven-character code that helps An Post’s sorting machines read mail in seconds.

Letters processed by An Post annually: over 600 million ·
Eircode introduced: 2015 ·
Optimal envelope size for machine sorting: 90 mm x 140 mm to 120 mm x 235 mm ·
Minimum font size on address block: 10 pt

Five key facts from official sources summarise the essentials — one pattern: every part of the address has a designated line, and deviating from it risks machine rejection.

How to address an envelope in Ireland?

Standard layout for Irish addresses

• Recipient name – first line
• House number and street name – second line
• Town or city – third line
• County or region – fourth line (always included, even for Dublin)
• Eircode – last line before country (if international)

An Post recommends no non-address text — no logos, decorative symbols, or extra words — inside the address block (An Post guidelines). Each element belongs on its own line, and the Universal Postal Union advises a maximum of 32 characters per line (UPU Ireland guideline).

Example address on an envelope

For a home in County Cork, a correctly addressed envelope would look like:

Mary Murphy
12 Green Lane
Bandon
Co. Cork
P72 H102

An Post (Ireland’s postal authority) stresses that Dublin postal districts (e.g., D4) should not be abbreviated — write “Dublin 4” in full on the line above the Eircode.

What is the address pattern in Ireland?

Components of a standard Irish address

Every Irish address begins with the recipient’s name, then narrows down from the most specific to the broadest location. According to AddressZen (address format specialist), the pattern is:

1. Recipient name (and organisation if applicable)
2. House number and street
3. Locality or townland (if needed)
4. Post town
5. County
6. Eircode
7. Country (for international mail)

This matches the template in the official UPU document, which also stresses left-justification and the use of block capitals for the entire address block (UPU Ireland guideline).

Eircode format: letters and numbers

Eircode is a seven-character alphanumeric code, always written as three characters, a space, and four characters — for example D02 X285 (AddressZen guides). The first three characters identify the routing area (usually a postal district or town), and the last four characters pinpoint the specific address. An Post places the Eircode on the final line of the address, just above the country name for international mail (An Post guidelines).

Why this matters: Without an Eircode, your letter cannot be sorted by An Post’s automated equipment. Hand-sorted mail takes longer and may be surcharged.

How do you correctly address an envelope?

Position of the address on the envelope

The recipient address must be placed in the bottom left-hand corner of the envelope front, according to the UPU Ireland standard (UPU Ireland guideline). Lines should be left-aligned and separated by single line spacing. The senders address (return address) goes on the back flap of the envelope, as recommended by An Post, or on the front upper left-hand corner per UPU — either is acceptable, but the back flap is the most common practice in Ireland.

Font and colour guidelines from An Post

• Ink: black or a very dark colour on a light background (An Post guidelines)
• Font: Arial, Century, or Courier in 10–13 point are preferred; avoid italics, underlining, or decorative fonts (UPU Ireland guideline)
• Length: no more than 32 characters per line (excluding spaces)
• Style: use block capitals for the entire address if handwritten; printed addresses are best (An Post guidelines)

Return address placement

The sender’s address should be written on the back flap of the envelope — the side that folds closed. If you prefer the front, place it in the top left corner, but keep its line length under 80 mm and use a smaller font (8 pt) so it doesn’t interfere with the machine reading zone (UPU Ireland guideline).

The pattern: The address block on the front is sacred — no logos, no decorations, no extra text. That space is reserved for the automated reader.

International mail: addressing a letter to Ireland from the USA

When sending from abroad, use the same local address format (name, street, town, county, Eircode) and add IRELAND in capital letters on the very last line (An Post guidelines). Allow 5–10 business days for delivery, as An Post does not guarantee exact transit times for international mail.

Step-by-step guide to addressing an envelope in Ireland

1. Write the recipient name — first line, no titles (Mr/Mrs optional but keep it simple). Source: An Post guidelines
2. Add the house number and street — second line, e.g. “12 Green Lane”.
3. Include the town or city — third line, e.g. “Bandon”.
4. Write the county — fourth line, e.g. “Co. Cork”. For Dublin addresses, write “Dublin 4” (not D4).
5. Add the Eircode — fifth line, e.g. “P72 H102”.
6. For international mail — sixth line: “IRELAND” in capitals.
7. Place the return address on the back flap in a smaller font.

Each step is supported by UPU Ireland addressing standard, which also recommends that the entire address be left-justified and free of punctuation.

Quotes from official sources

“Address should be printed on the back of an envelope. No non-address text should appear within the address block.”

— An Post, Speed up your post guidelines (source)

“All mail must include the sender’s address on the front upper left-hand corner of the envelope. The sender’s address line should not exceed 80 mm in length and font size 8 is preferred.”

— Universal Postal Union, Ireland addressing guideline (source)

Two authoritative bodies offer slightly different return address positions. The trade-off: following the UPU front-upper-left rule keeps you compliant for international mail, while An Post’s back-flap recommendation is the Irish domestic norm.

Summary

Getting an envelope right in Ireland comes down to five lines and one code. For anyone sending mail to an Irish address, the choice is clear: follow the Eircode format, keep the address block clean, and place the return address on the back flap. Ignore these rules, and your letter could be delayed by days — or returned at your expense.

For detailed official guidelines on addressing envelopes to Ireland, including Eircode placement and international mailing tips, see the complete guide.

Frequently asked questions

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