# NI Postcodes The OS NI Postcode Collection is a complete, analytical and authoritative postcode dataset for Northern Ireland. It is designed to provide a detailed view of postcodes. The collection gives you access to the most current and comprehensive postcode data for Northern Ireland. It provides all postcodes supplied in Royal Mail's Postcode Address File (PAF) and geometries from Ordnance Survey of Northern Ireland. {% hint style="info" %} Postcodes were originally designed as a way to sort mail into different delivery bags efficiently and had no association with the real-world places that mail was being sent to. Over time the association between the postcode and physical locations has grown, so they are used as shorthand to refer to places or the people at those places. Today, some postcode users need a geometry, while others only need the code itself. {% endhint %} ### Common use cases for postcodes The following table gives a breakdown of common use cases for postcodes and the type of geometry (or not) that is best suited for those use cases:
Use CasePointsPolygonsPostcode Attribute
Routing / NavigationYesNoNo
Lightweight geocodingYesNoNo
Statistical aggregation and reportingYesYesYes
Territory mapping and assignmentNoYesNo
VisualisationYesYesNo
Data anonymisationNoNoYes
Service eligibility checksNoYesYes
Data linkingNoNoYes
Not all use cases relate to real-world locations, and you might only need to know the postcode attribute and possibly some of the associated metadata. For example, when a postcode is used to anonymise individuals, it is not always necessary to know where that individual is. Some use cases listed in the table could use either points or polygons based on your specific requirements or personal preference. We have added the same attributes to both feature types, so you can choose what suits you and still have access to the relevant information. For example, Postcode Unit Point features and Postcode Unit Area features will include the attributes relating to different postcode elements, postcode types and postcode delivery point counts. ### Collection applications The OS NI Postcodes Collection allows you to: * Access all postcodes in Royal Mail’s PAF in Northern Ireland. * Access postcode units which have been designed to be used in multiple applications, including GIS and web mapping applications. * Perform powerful analytics, underpinned by unrivalled OS accuracy, using additional enriched attribution (detailed below). * Ensure your postcode data is always up-to-date with up-to-monthly updates. * Produce visualisation and reporting of data for the provision of services and more effective communicating of information to citizens. * Improve data aggregation or clustering (for example, anonymising individual people at risk or or predicting load on networks). * Determine asset management, territory assignment and service eligibility. ### Key elements * Rich attribution ensures the data is straightforward to navigate and query. The enriched attribution includes, but is not limited to, the following: * New area, district and sector attribution which makes it easier to analyse data at these scales. * Number of delivery points per postcode. * Determine whether a postcode has small or large users. * Plug and play – the data is simple and quick to implement as you don't need to pre-process it before you use it, including providing spatial indexing in GIS applications. * Consistency with address and to support spatial indexing out of the box. * Full UK postcode coverage available via accessing the OS GB Postcodes and OS NI Postcodes Collections together; the identical schemas in the two collections enable compatibility. * Cross-references make it easy for you to link data in this collection with data from other organisations and other collections in the OS NGD. ### FAQs Frequently asked questions (FAQs) about this collection and detailed answers are available from the [FAQs page](https://docs.os.uk/osngd/getting-started/faqs#postcodes-data-faqs). ### Coverage Northern Ireland. ### Default coordinate reference system European Terrestrial Reference System (ETRS89: EPSG: 4258) ### Temporal filtering The earliest date on which you can request a one-off snapshot of a date in the past for data in this collection is noted at the top of the individual feature type pages. {% hint style="info" %} ### Collection update date and temporal filtering Please note, postcodes data is updated on the seventeenth or next working day of each month. If you have a daily recipe, then you'll receive blank files for all other days. If you have monthly recipe, then this will be delivered to you on the first of the following month. {% endhint %} ### Supply formats GeoPackage, CSV (comma-separated values) or GeoJSON. ### Supply mechanism OS NI Postcodes Collection data can be accessed through the [OS Data Hub](https://osdatahub.os.uk/) via OS Select+Build (the bespoke OS NGD download service). It can't be accessed through OS NGD API – Features or OS NGD API – Tiles. ### Using our data * Included in the [Public Sector Geospatial Agreement](https://www.ordnancesurvey.co.uk/customers/public-sector/public-sector-geospatial-agreement) (PSGA) – therefore, it's free at point of use for Public Sector organisations. You can [check if your organisation is a member of the PSGA on the OS website](https://www.ordnancesurvey.co.uk/customers/public-sector/psga-member-finder). * Available to OS Partners for commercial resell in your solutions. * Available for organisations to try out for free for three months under the [Data Exploration Licence](https://www.ordnancesurvey.co.uk/licensing/data-exploration-licence#overview); this licence is primarily designed for organisations either considering becoming an OS Partner or who want to trial OS Premium data before working with an existing OS Partner.