Holding answer received on 06 September 2019
The Electoral Commission undertakes periodic research into the accuracy and completeness of the electoral registers in the UK. Information is collected from a sample of households, and details of residents are then matched against actual register entries to generate the estimates of accuracy and completeness.
The last study assessed the December 2015 registers and was published in 2016. The Commission found that:
- In Great Britain, the local government registers were 84% complete, meaning that 16% of eligible electors did not have a correct register entry.
- In Northern Ireland, the local government register were 79% complete, meaning that 21% of eligible electors did not have a correct register entry.
By applying these estimates to Office for National Statistics data, the Commission calculated that:
- In Great Britain, between 7.8 and 8.5 million eligible people were not correctly registered.
- In Northern Ireland, between 275,000 and 330,000 eligible people were not correctly registered.
This does not mean that these people were entirely missing from the registers; many will have had an entry at a previous address. It is not possible to determine this figure because of the absence of a consistent, unique identifier for individual electors on the registers.
The results of the Commission’s next accuracy and completeness study will be published in the coming months.