Voters' registers allow election authorities to determine who may exercise the right to vote in each of the processes.
It is therefore essential for the data to be undergo constant revision, which will guarantee that requisite new entries and deletions are made and that duplications are avoided.
In the modern permanent registers of most industrialised countries, updating is normally done regularly, from every one to six months, so the register used in an electoral process is a document that shows the most current additions and deletions of names over the previous period.
The maintenance of voters lists requires complex operations. In countries like the United States and Canada, for example, it is calculated that between 16 and 18 percent of their entries are modified annually, mostly as a result of address changes.
Besides periodic updating, electoral regulations usually stipulate specific updating or rectification of the voters' register at election times, with a designated period of time for the lists to be displayed and citizens to report inaccuracies. This usually goes hand in hand with particularly swift administrative and/or judicial procedures, to ensure that the necessary modifications are made and are effective on election day.
It is evident that with this operation that the permanent voters list offers the greatest advantage for registration procedures in each election.
