Single non-transferable vote (SNTV) is a multi-winner electoral system in which each voter casts a single vote. Like first-past-the-post voting, SNTV uses basic plurality to allocate seats. Being semi-proportional, SNTV gives a chance for both small parties and large parties to be represented. Under SNTV, a single party seldom will take all seats in a city or district.
SNTV is a combination of multi-member districts and each voter casting just one vote. SNTV can be considered a variant of dot voting where each voter has only one point to assign. It can also be seen as a variant of limited voting where each elector has one vote, or as a simple version of single transferable vote where votes are not transferred. Unlike block voting or limited voting, where voters can cast two or more votes, under SNTV each voter casts just one.
SNTV retains many of the problems of first-past-the-post voting (first-preference plurality voting), such as high incidence of wasted votes. As a result it is sometimes viewed skeptically by social choice theorists. However, its relative simplicity and easy vote-counting makes the system particularly popular for small elections to offices such as city councils, particularly when compared to the more-intricate single transferable vote (STV) system, and has resulted in the method becoming commonly used for ordering open party lists.
Voting In any election, each voter casts one vote for one candidate in a multi-candidate race for multiple offices. Posts are filled by the candidates with more votes than the others (plurality voting). Thus, in a three-seat constituency, the three candidates receiving the largest numbers of votes would win office, even if none of them take a majority of the votes.
SNTV, like single transferable vote, can be used with non-partisan ballots, in election contests where there are no parties.Amy, D.J. Behind The Ballot Box: A Citizens Guide To Voting Systems. Praeger Publishers Westport, CT (2000) 128. Print
Example Three seats are to be filled among five candidates: A, B, C, D and E fielded by 3 parties X, Y and Z.
Votes Candidate Party2,718EY1,999DZ1,996CZ1,804BY819AX E, D and C are the winning candidates. Thus, Party Z gets two seats and Party Y gets one seat. No one party took all the seats as might have been the result under first past the post or plurality block voting.
But counting the votes by party gives these vote tallies: Party Votes Percent SeatsY4,522481Z3,995432X81990
Party Y has more votes than Party Z, but receives fewer seats because of an inefficient spread of votes across the candidates. If Party Y's two candidates had had more equal vote tallies, it would have won two seats and Party Z only one. Or if Party Z's candidates had received less equal vote tallies, Party Y would have won two seats even if its candidates were not equally popular. (There is more chance in SNTV than a more orderly system of PR, such as list PR or STV.)
If either party had risked trying to win all three seats, causing more vote splitting among supporters of Parties Y and Z, then A of Party X might have won a seat and either party Y or Z would then have taken one fewer seat.
Given candidates to be elected, Candidate A can guarantee success by receiving one more than of the votes (the Droop quota), because +1 other candidates cannot each receive more than Candidate A (too many would not pass Droop quota)
To determine the successful candidates, candidates' vote tallies are compared with the vote tallies of others, not with a theoretical threshold or quota. In the 2020 Vanuatuan general election, using SNTV, as few as 5 percent of the vote was enough to be elected in a seven-seat district, where about 13 percent is Droop quota.
SNTV compared to block voting and limited voting For example, 10,000 voters vote to elect three members. Cumulative voting is not used so each voter may not cast more than one vote for a single candidate.
Under block voting, each voter may cast up to 3 votes in the 3-seat district Under limited voting, each voter may cast 1 or 2 votes in the 3-seat district Under the single non-transferable vote, each voter may cast 1 vote in the 3-seat district
Party A has about 35% support among the electorate (with one particularly well-liked candidate). Party B has around 25% support (with two well-liked candidates). The remaining voters primarily support independent candidates, but mostly lean towards party B if they have to choose between the two parties. Vote percentage under block and limited voting is the percentage of voters who voted for the candidate, not percentage of all votes cast.
CandidatePartyPlurality block votingSingle non-transferable votePlurality block votingLimited votingVotes%Elected?Votes%Elected?Votes%Elected?Candidate A1Party A370037%Yes320032%Yes200020%YesCandidate A2Party A360036%Yes160016%Yes9009%Candidate A3Party A355536%Yes140014%7007%Candidate B1Party B260026%195020%Yes110011%YesCandidate B2Party B250025%175018%9509.5%YesCandidate B3Party B235024%102510%6006%Candidate I1Independent110011%110011%8508.5%Candidate I2Independent9509.5%9009%7507.5%Candidate I3Independent8508.5%8008.5%6006%Candidate I4Independent8008%7507.5%5505.5%Candidate I5Independent7507.5%7007%5005%Candidate I6Independent6006%6506.5%4504.5%TOTAL votes cast224051722510000TOTAL possible votes300002000010000Voters100001000010000100%
The three most-popular candidates according to voters' first preferences are elected, regardless of party affiliation. Under the single non-transferable vote (like in block voting and limited voting) the number of seats are sometimes not proportionately allocated. Over-optimism (running too many candidates) and vote splitting is punished. But each popular party that runs one candidate is assured of success to that degree anyway. In this case, even though the most-popular party ran three and risked vote splitting, it did elect one member. Single non-transferable vote described here is not a type of approval voting. Under block voting, the three candidates of the most-popular party are elected if its supporters vote along party lines. In this case a party with only 35 percent support took all the seats. Under limited voting, it is most likely that the party with a plurality takes two seats (or the same number of seats as the number of votes each voter has), and another less-popular party receives the remaining seat(s). STV (not shown here) would see each party take its due share of seats if voters mark their preferences along party lines. Thus Party A and Party B would take one seat for sure, with the third seat going to Party B due to it being the choice of supporters of the Independents if it came to choice of those two main parties. The three most-popular candidates according to vote tally are elected, regardless of party affiliation, but not necessarily in accordance with first preferences.
Non-proportionality SNTV increases political fragmentation and representation of small parties compared to first-past-the-post voting, that is, it produces mixed representation of large and small parties where no party takes all the seats.Lijphart, A. Pintor, R.L. Sone, Y. “The Limited Vote and the Single Nontransferable Vote: Lessons form the Japanese and Spanish Examples.” Electoral Laws and their Political Consequences. Ed. Bernard Gromfman and Arend Lijphart. Agathon Press, INC., New York 2003. 154-169. Print. But not having transfers, SNTV sees more votes wasted than under STV due to votes being placed on un-electable candidate or due to surpluses received by successful candidate over and above the quota used in STV elections that are not able to be transferred under SNTV.A Report on Alberta Elections, 1905-1982) In 2007 Scottish local authority elections, only 73 out of 1222 members were not in winning position in the first round, so only 73 owed their wins to vote transfers."Local authority elections in Scotland, May 2007" https://www.electoral-reform.org.uk/wp-content/uploads/2017/06/2007-Scottish-local-elections.pdf accessed April 25, 2025 (But that is not to say that first past the post or block voting would have produced the same winners. In each district, under SNTV multiple parties elected representatives, not the likely result under those two non-proportional systems.)
Representation elected under SNTV is more proportional when political parties have accurate information about their relative levels of electoral support, and nominate candidates in accordance with their respective levels of electoral support or when all parties suffer from poor information of that sort. Knowing the share of the votes a party will take allows it to avoid vote waste due to lessening the chance of vote splitting and inefficient placement of party support. Under 'perfect' strategic voting and strategic nomination, SNTV would be equivalent to the D'Hondt (Jefferson) method of proportional representation.
The number of wasted votes in an SNTV election is generally lower than in first past the post elections.A Report in Alberta Elections, 1905-1982
SNTV generally does not achieve equal seats-to-votes ratios, because it is difficult to accurately judge their strength when deciding how many candidates to field (strategic nomination) and difficult to direct party supporters as a whole to spread their votes efficiently. If they field too many, supporters' votes might be split across too many candidates. The party votes might spread their vote numbers to the point where all of a party's candidates lose to a less thinly spread opposing party. If a party fields too few candidates, they might elect all their candidates but not win seats proportional to their level of support, and the winning candidates would have more support than necessary and thus wasting votes.
The risks of poor strategic nomination are not equal for parties of various strengths. A large party would have much more to lose from the split vote effect than to gain from avoiding the wasted vote effect, and so would likely decide to err on the side of fielding fewer candidates (but probably not less than their existing number of seats). A small party with little representation would be more risk-tolerant and err on the side of too many candidates, hoping to gain as many seats as possible, perhaps even winning more than its proportion of the electorate if they can edge out candidates from larger parties with just a few votes. As well, a small party running just one candidate would not suffer from vote spitting, while a larger party running four or more may suffer from that.
SNTV electoral systems typically produce more proportional electoral outcomes as the size of the electoral districts (number of seats in each constituency) increases.Farrell and McAllister, The Australian Electoral System, p. 33
Strategic voting Strategic voting in a single non-transferable vote system is frequent. Casting only one vote, a rational voter wanting to maximize the number of seats captured by his party should vote for a candidate of the party that has a chance of winning, but one that will not win by too great a margin and thus take votes away from party colleagues. This creates opportunities for strategic nominations, with parties nominating candidates similar to their opponents' candidates in order to split the vote. Like all multiple-winner selections, parties find it advantageous to run a range of candidates in SNTV elections. Having candidates of both genders, two or more ethnic or language groups, and different home areas and socio-economic levels may yield better returns. But due to potential adverse results of vote splitting, the size of a party's slate in a district may need to be carefully assessed.