Question to the Ministry of Housing, Communities and Local Government:

To ask the Secretary of State for Housing, Communities and Local Government, what assessment she has made of (a) the duplication of scanned signatures and (b) technical problems with the Electoral Registration Officer Portal since its introduction in 2023; how many (i) local authorities and (ii) postal vote applications have been affected; if she will list which local authorities have been affected; and whether there were periods when duplicate signatures could not be checked.

On 13 May 2025, MHCLG identified a software bug with the batch application upload functionality on the Electoral Registration Officer Portal (ERO Portal), which had existed since 21 March 2024.

The bug could lead to misallocated signature images for certain elector records stored in local authority Electoral Management Systems (EMS). The issue would only present where an elector had applied for a postal vote via a paper form, where an ERO had included their application in the batch paper upload feature of the ERO Portal, and where there was a large volume of processing of batched application uploads. Our investigation also concluded that the issue was more likely to present where there were network performance issues. The issue was fixed on 14 May 2025, and further cases have since been prevented from occurring

An analysis conducted on the data held in the ERO Portal was used to identify duplicated signature images in the data. This analysis identified a potential 112 cases of exact duplicate images caused by this issue across the ERO Portal data, out of a total of 2,257,946 postal vote applications. In total, we identified 64 Electoral Registration Offices, across 67 local authorities, where we had identified a duplicated signature

Due to the data retention periods of the ERO Portal, the data analysis was only able to check for duplicates between 14 May 2024 and 14 May 2025. EMS suppliers have been able to provide support for ERO teams to check for duplicated signatures between 21 March 2024 and 14 May 2024

ERO Portal users across local authorities were updated throughout the investigation. MHCLG engaged directly with local authorities believed to be impacted by this bug to inform them of potential cases so they could be investigated and rectified by individual ERO teams. We continue to work closely with EMS suppliers to support impacted ERO teams.

Technical issues on the ERO Portal are routinely documented and communicated through digital service governance processes. As part of this, any lessons that can be taken from technical issues are discussed and analysed, whilst preventative mitigations are then adopted in software development practises. We also work closely with the LA elections sector to collate and evaluate user feedback, which feeds directly into our roadmap for continuous product improvements.