The Electoral Commission informs me that they collect from every ERO, and publish, annual electoral registration statistics covering a range of topics including the number of electors on the registers, response rates to the annual canvass, numbers of additions and deletions on the registers and levels of carry forward.
This data collection will be more frequent during the transition to individual electoral registration (IER).
The Commission further informs me that they report periodically on the overall levels of accuracy and completeness of the electoral registers. Such studies are costly to conduct and it is not therefore feasible to conduct them annually. There are two such studies planned as part of the Commission's approach to monitoring the implementation of IER.