Accuracy and completeness of the December 2015 electoral registers


In this report, we look at the effect of Individual Electoral Registration (IER) on the accuracy and completeness of the electoral registers.

To do this, we compare the electoral registers from December 2015 (after IER was introduced) with those from February and March 2014 (when the household system was still in place).

Accuracy and completeness

Accuracy and completeness

The local government registers were 91% accurate and 84% complete.

The parliamentary registers were 91% accurate and 85% complete.


This means that during the transition to IER (10 June 2014 to 1 December 2015) the overall accuracy of the registers increased, by an estimated four percentage points. 

Completeness appears to have remained largely stable, with a decline of less than 1 percentage point which is not statistically significant.


These estimates are for Great Britain as a whole. It’s likely that accuracy and completeness will vary across different local council areas, due to the demographics of the local population as well as registration practices.

You can also view our reports and overviews for all areas of the UK.

Decreases in completeness

At the overall level, the change in completeness from 85% before IER was introduced to 84% afterwards is small.

However, there are more notable decreases for particular socio-economic groups. Our research confirms the correlation between certain demographics and lower or higher levels of completeness.

Age and mobility are still the variables with the strongest impact: the young and those more likely to move home are less likely to be registered.

Decreases in completeness

Last updated: 24 September 2019
Next review: 22 July 2020