Most people who vote in tomorrow’s general election will vote in person, in one of around 40,000 polling stations that will be open from 7am to 10pm. All voters should have received a poll card no less than a week before election day. You should present this at the polling station when you vote. Each voter is then given a ballot paper on which to mark their vote. The paper bears an alphabetical list of all the candidates standing in that constituency. In addition to your elector number, your ballot paper will carry an “official mark” which should be visible from both sides of the paper. This will usually be stamped with a special instrument immediately before it is given to you; but some papers may have a pre-printed mark or barcode instead.
… Today, to prevent fraud, every ballot paper carries a Serial number as well as a unique official mark. This means that, although the ballot in UK elections is supposed to be secret, it is theoretically possible to trace each vote to the voter who cast it. It is, however, illegal to do so.
All ballot papers, counterfoils and related paperwork are sealed and stored securely for one year after the election. They are then destroyed.
…A significant minority of voters will have opted to vote by post rather than in person. For the 2010 general election, 6,996,006 postal ballot papers were issued – an increase of 1,633,505 on 2005, and equivalent to 15.3 per cent of the electorate. Well over 1 million of these were not returned before the close of polling, while a further 183,453 were spoilt. This left 5,596,865 postal votes that counted towards the result of the election.