540. It is especially important to consider the effects of nullifying the vote at an entire polling station. In principle, such cases only affect the vote at that polling station, and not the entire electoral process. However, it is possible that annulling the vote at several polling stations will have an impact on the election as a whole. The immediate effect of nullifying a vote is that the votes at that polling station will be excluded from the general tally of the votes cast in the election in question; but this could result in a new tally that alters the overall winner. In some EDR systems, for example in Bangladesh, it means the possibility of a new vote at the polling stations affected if there are grounds for doing so. Almost all electoral legal frameworks establish the principle, formulated in either positive or negative terms, that if the annulment of the vote at a particular polling station or set of polling stations can affect the outcome or validity of the entire election, either a new vote or a new election will be required. 541. Some legal frameworks establish the principle in negative terms, prescribing that new elections shall not take place if it appears that the new vote (at the specific polling station) would not have any impact on the general outcome of the election. Others put it in positive terms, establishing that there should be a new election if the votes annulled can alter or affect the outcome of the election or are enough to decide whether a party will continue to enjoy legal standing. 542. While several countries allow for the possibility of the new vote being held only at those polling stations in which the vote has been annulled (or if an election was not held at a polling station), that is, a partial revote, some provide that new elections must be held in the whole country. 543. When there is a new tally of the votes cast, the certification issued to a slate or a candidate is revoked, and the candidate or slate that emerges as the winner as a result of the annulment of the votes cast at one or several polling stations is then certified. 177 7. Basic elements of EDR systems • any error in applying the electoral formula; • other defects in the vote count, for example, arithmetical errors in or alterations to the tallying; • the preparation or signing of protocols or certifications by persons not authorized to do so; • the use of unauthorized forms; • the absence, destruction or disappearance of electoral documentation; • the lack of the signature of some or all polling officers; • any tampering with the so-called electoral package or bag; and • delivery of the electoral packages, petition forms or bags from the polling station to the next-highest level of the electoral machinery after the deadline for doing so has passed.