The Electoral registration in the United Kingdom, which states that the electors must be registered after the election, did not take place until 1832 as a result of the Reform Act 1832.
Electors must be on the electoral register in order to vote in elections and referendums in the UK. Since 1832, only those registered to vote can do so, and the government invariably runs nonpartisan get out the vote campaigns for each election to expand the franchise as much as possible. 
