AddressBase Core Data Issues, Service Disruptions and Planned Maintenance

This page provides the details of known data issues and service disruptions impacting the AddressBase Core product.

Planned maintenance starting: 05/08/2025 to 08/08/2025

Disruption description

AddressBase Core orders will be suspended from Tuesday 05 August until Friday 08 August 2025.

Impacts of the disruption

From Tuesday 05 August to Friday 08 August 2025, the distribution of new customer orders for AddressBase Core will be suspended. When the suspension is removed, any customer orders placed during the suspension will be distributed and available to customers.

When to expect the next update

We anticipate for the maintenance disruption to be resolved by Friday 08 August 2025. We apologise for any inconvenience this service disruption may cause.

A further update is expected on Monday 11 August 2025.

Live known data issues

Incorrect GSS code values for address records in Sheffield and Barnsley.

The AddressBase Core product refresh scheduled for the week commencing 11 August 2025 will only contain changes to correct the GSS codes for Sheffield and Barnsley. This means changes from Local Authorities, Royal Mail or Ordnance Survey will not be available in the weekly product refresh.

  • For customers taking a full supply of AddressBase Core, the full supply will still be received. However, the only change contained within the data will be the updates to the Sheffield and Barnsley GSS codes. No other address records will have changed, in comparison to the previous release.

  • For customers taking AddressBase Core Area of Interest (AOI) Change Only Update (COU) orders will only receive updates to tiles containing Sheffield and Barnsley GSS codes. If your AOI does not contain tiles with Sheffield or Barnsley GSS Codes then your COU updates will be blank for the week commencing 11 August 2025. Customers will be contacted directly, prior to the release, if identified as likely to receive blank AOI COU orders.

  • The AddressBase Core product refresh scheduled for the week commencing 19 August 2025 will include two weeks’ worth of change.

Data issue description
Last Update

An issue was encountered following the change in GSS codes for Sheffield and Barnsley that took effect on 01 April 2025. This has resulted in AddressBase Core currently displaying the historic GSS code.

The previous and current GSS code changes as of 01 April 2025 are detailed in the table below:

Local Authority District

Current AB Core (historic) GSS Code

Correct GSS Code

(Effective from 01 April 2025)

Barnsley

E08000016

E08000038

Sheffield

E08000019

E08000039

GSS code fix planned for the week commencing 11 August 2025, with full implementation during the week commencing 19 August 2025.

10/06/2025 – Under investigation

To report an issue not currently listed here, please visit the 'Contact us' page on the OS website.

Last updated

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