> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/os-open-names/os-open-names-getting-started-guide/obtaining-os-open-names-data.md).

# Obtaining OS Open Names data

## Product supply <a href="#id-2.1-product-supply" id="id-2.1-product-supply"></a>

The OS Open Names product is supplied in three formats (CSV, GML and GeoPackage) as an online download and as an application programming interface (API), both of which can be accessed from the [OS Data Hub](https://osdatahub.os.uk/).

## Update schedule <a href="#id-2.2-update-schedule" id="id-2.2-update-schedule"></a>

Updates are supplied quarterly (January, April, July and October) and are provided as a complete resupply. Any features that are deleted between supplies are not included in the resupply.

## Coverage <a href="#id-2.3-coverage" id="id-2.3-coverage"></a>

OS Open Names covers named places for Great Britain.

## File size <a href="#id-2.4-file-size" id="id-2.4-file-size"></a>

The approximate file size of each data format is as follows:

* CSV: 1.65Gb
* GML: 9.1Gb
* GeoPackage: 2.1Gb

## File structure <a href="#id-2.5-file-structure" id="id-2.5-file-structure"></a>

### CSV <a href="#id-2.5.1-csv" id="id-2.5.1-csv"></a>

The file structure of OS Open Names CSV format supply is:

* Root folder: *Readme.txt* (summary of supplied data).
  * Doc folder: *OS\_Open\_Names\_Headers.csv* (description of column headers) and *licence.txt* (important licencing information).
  * Data folder: 819 files in CSV format.

*Each file contains data for a 20x20km area labelled with the corresponding grid reference, for example, HP40.csv.*

The structure of OS Open Names supplied in CSV is described in the [Technical Specification](/os-downloads/products/addresses-and-names-portfolio/os-open-names/os-open-names-technical-specification.md).

### GeoPackage <a href="#id-2.5.2-geopackage" id="id-2.5.2-geopackage"></a>

The file structure of OS Open Names GeoPackage format supply is:

* Root folder: *Readme.txt* (summary of supplied data).
  * Doc folder: *licence.txt* (important licencing information).
  * Data folder: *opname\_gb.gpkg* (single file in GeoPackage format).

*This file is a self-contained database*.

The structure of OS Open Names supplied in GeoPackage

### GML <a href="#id-2.5.3-gml" id="id-2.5.3-gml"></a>

The file structure of OS Open Names GML format supply is:

* Root folder: *Readme.txt* (summary of supplied data).
  * Doc folder: *OS\_Open\_Names\_Headers.csv* (description of column headers) and *licence.txt* (important licencing information).
  * Data folder: 819 files in GML format.

*Each file contains data for a 20x20km area labelled with the corresponding grid reference, for example, HP40.gml.*

The structure of OS Open Names supplied in GML format is described in the [Technical Specification](/os-downloads/products/addresses-and-names-portfolio/os-open-names/os-open-names-technical-specification.md).

## Metadata <a href="#id-2.6-metadata" id="id-2.6-metadata"></a>

OS Open Names metadata is ISO 19115 UK GEMINI 2 compliant. For more information, see [OSOpenNames.xml](https://www.ordnancesurvey.co.uk/xml/products/OSOpenNames.xml).


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