What is Eircode?

What is Eircode?

Eircode is Ireland’s postcode system, launched in July 2015. An Eircode is a seven-character alpha-numeric postcode. Each Eircode is unique to a postal address and its geographic location. 

Over 35% of addresses in Ireland share their address with at least one other property, making it difficult to find the location of a specific address. Unlike other countries where postcodes define a cluster or group of addresses, in Ireland a unique Eircode is assigned to each residential and business postal address. 

A65 F4E2

How Eircode Works

An Eircode is made up of two parts, a Routing Key, and a Unique Identifier.

The Routing Key consists of three characters. This is a combination of numbers and letters and identifies the principal post town related to a building or property’s postal address. The Routing Key characters are the same for all Eircodes assigned to addresses within that postal area.

The second part is the Unique Identifier and consists of four characters. The unique identifier is made up of numbers and letters. The Unique Identifier is unique to an address and its geographic location – it distinguishes one address from another within a postal area.

A typical Eircode might read A65 F4E2.


An Eircode is seven character alpha-numeric code made up of two parts.

Routing Key:


The first part (a Routing Key) consists of three characters and defines a principal post town span of delivery.


Unique Identifier:


The second part (a Unique Identifier) is unique to an address and distinguishes one address from another.

When Eircode launched in 2015, Eircodes were assigned to over 2.2m postal addresses. Eircode used a postal address database supplied by An Post GeoDirectory DAC (a subsidiary of An Post) to assign these Eircodes. An Post GeoDirectory maintains the address data, amending and adding addresses and geographic locations to the database.

Each month an updated database is supplied to Eircode by An Post GeoDirectory. Eircodes are then assigned to any new postal addresses that have been added to the database. For more information visit Getting an Eircode.

Once a new Eircode has been assigned the postal address and geographic location are added to the Eircode Finder, a public website that allows you to search for Eircodes by address or map.

The Eircode database is also available through a licence agreement for use by businesses or organisations – for example delivery companies, service providers or emergency services.

Some frequently asked questions about Eircode

Are Eircodes sequential?

Eircodes are not sequential by design. As buildings are built, altered, and demolished, Eircodes are assigned or retired, which would cause sequential codes to fall out of sequence very quickly. 

For example:

  • When a new building is built between two existing buildings
  • When an existing building is split into multiple flats or business premises
  • When an existing building which is split into multiple flats is converted into a single residence or business premises.

As Eircodes are not sequential the assignment or retirement of an Eircode does not affect any Eircodes already existing in the area.

Which Letters and Numbers are used in Eircodes?

The letters and numbers used when creating Eircodes have been carefully considered to avoid verbal or visual confusion. For example, the number zero is included in the character set used for Eircodes, but the letter ‘O’ is not. This was a deliberate design decision to ensure that two visually similar characters do not appear in an Eircode.

Systems that use Eircodes are advised to follow the technical guidelines provided by Eircode which would result in the number zero, or a letter ‘O’ being read and interpreted correctly as the number zero, even in cases where someone has incorrectly provided the Eircode using a letter ‘O’.

Similarly, the order in which the alpha-numeric characters appear in an Eircode is reviewed to ensure slang names, offensive abbreviations or words have been excluded.

Are county details used in Eircode?

Like postcodes in other countries, Eircode helps the parcel and postal industry find the correct addresses. The first 3 characters of the Eircode, called the Routing Key, identify the postal area relating to a building or property’s postal address. There are 139 different postal areas in use in Ireland. These postal areas are not county specific and may cross over county borders. 

Using county or city details in the Eircode would have limited the available alpha-numeric combinations. The only exception to this is the Dublin postal district numbers which have been in use for many years.

For more information visit Eircode Frequently Asked Questions.