🆕OS ESG FAQs

General FAQs

What file formats are available for the OS ESG?

OS ESG data is available in two easy-to-use formats: GeoPackage and CSV (comma-separated values). More information about both formats is available on the 'Product supply' page of the OS ESG Overview.

Is COU data available?

Monthly COU (Change-Only Update) supplies are available for CSV (comma-separated values) files only; they are not available for GeoPackage files. More information about both formats is available on the 'Product supply' page of the OS ESG Overview.

How do I get started with using the OS ESG?

Our OS ESG Getting Started Guide will help you to get started using the product; the guide contains detailed instructions on accessing and / or converting GeoPackage data, using the CSV dataset in a database, and useful links to additional resources for getting the most out of the OS ESG.

A helpful introductory Lightning Talk on the OS ESG is also available on our 'More than Maps' site (a self-serve platform that provides a one-stop shop for all your OS technical geospatial support, including tutorials and demonstrators).

What OS ESG release aligns to the relevant AddressBase Premium Epoch version?

The OS ESG references unique street reference numbers (USRNs) in AddressBase Premium; however, there is a disconnect in publication schedules between the two products, with the OS ESG publishing monthly and AddressBase Premium publishing every six weeks.

Please see the table on the 'Product supply' page of the OS ESG Overview for a comparison of publication schedule alignments between the two products for this year.

What are the differences between the OS ESG and AddressBase Premium specifications?

Due to the structure of the datasets and customer feedback, we purposefully ensured that the OS ESG aligns with the AddressBase Premium specification. This meant that we had to tweak the field character limits in both the SAO text and Area name fields in the OS ESG:

• sao_text: Has a field character limit of 90 in AddressBase Premium and 400 in the OS ESG.

• area_name: Has a field character limit of 40 in AddressBase Premium and 100 in the OS ESG.

The reason for increasing the character limits in these two fields for the OS ESG is to ensure all the information is presented properly and isn't truncated; thereby also accommodating any Gaelic variations for names.

Are the classification schemes in the OS ESG and AddressBase Premium different?

Yes. AddressBase Premium uses the AddressBase Classification Scheme, while the OS ESG uses the OS Emergency Services Gazetteer Classification Scheme. While these classification schemes have different names, they follow the same structure, i.e. Quaternary level classification.

Why are there features with no data present in the SAO text field?

There are a number of features that OS does not have any information for, and these fields will be Null in the data. For example, no intersecting road information is recorded for junctions without any named or numbered roads; as such, the SAO text field will be Null for these junctions.

For road junctions data, why are some streets listed both with and without an apostrophe? For example: CUCKOO LANE | ST STEPHEN'S WALK | ST STEPHENS WALK.

All possible variations of a street name are included in the OS ESG. This information is modelled and created using OS Transport Network data.

Why are some bridges not showing in the OS ESG?

To avoid duplication, bridges with a unique property reference number (UPRN) in the National Address Gazetteer (NAG) won't appear in OS ESG data; however, they will still be shown in the OS Addressing products (for example, AddressBase Premium).

The following types of bridges are excluded from the OS ESG:

• Unnamed bridges (including footbridges) with no networks crossing over them and an unnamed watercourse passing beneath them.

• Unnamed footbridges with unnamed paths crossing over them and either an unnamed watercourse or no network passing beneath them.

Are subways included in the OS ESG?

No, subways are not yet included in the OS ESG. They will be released into OS National Geographic Database (OS NGD) Compound Structure Feature Type in March 2025 and at a later date into the OS ESG.

Underpasses, however, are now included in the OS ESG (since December 2024). The following will be excluded:

• Unnamed bridges (including footbridges) with no networks crossing over them and an unnamed watercourse passing beneath them.

• Unnamed footbridges with unnamed paths crossing over them and either an unnamed watercourse or no network passing beneath them.