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.

Recent 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 only contained changes to correct the GSS codes for Sheffield and Barnsley. Changes from Local Authorities, Royal Mail or Ordnance Survey were not available in this week's product refresh.

• The AddressBase Core product refresh scheduled for the week commencing 19 August 2025 will include two weeks’ worth of change from Local Authorities, Royal Mail and Ordnance Survey.

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 12/08/2025 - Fix successfully implemented and released week commencing 11/08/2025.

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