Over-votes in past elections due to vote counting machine glitches?

MANILA, Philippines – In the 2010 elections, over 90% (511 of 557) of valid ballots in one clustered precinct in Barangay Maliksi III, Bacoor, Cavite were not counted due to over-voting. This covered all positions on the front of the ballot: president, vice-president, senator, and party-list positions.

Over-voting happens when a voter shades or chooses more than the intended number of winners for a particular contest.  

In the same year, another precinct, this time in Pantukan, Compostela Valley also registered an abnormally high over-voting rate. If the machine counts were to be believed, some 74% and 73% of voters in this precinct over-voted for the senator and party-list positions, respectively.

These were some of the extreme cases of over-voting which are evident from a scrutiny of precinct-level data from the Transparency Server, which provides quick access by the public to precinct-level results in real time.

In the 2013 elections, over-votes for the party-list contests affected almost 2.8 million ballots. This number is more than twice the number of votes obtained by Buhay, the group that got the most number of votes in the party-list race.

The number of over-votes for the senatorial contest was close to 0.7 million, almost equal the lead of Senator Gregorio "Gringo" Honasan, who edged out Richard Gordon for the 12th spot in the senatorial race. The number of over-votes still excludes the precincts that did not transmit to the transparency server, so the number could actually be higher.

Individual voters should make sure that the Board of Election Inspectors notes if their ballots are incorrectly read by the vote counting machines – as in the case of unintended over-voting.

According to lawyer Ona Caritos of the Legal Network for Truthful Elections (Lente), if a significant number of ballots is tampered with, leading to unintended over-voting, this could be used as a basis for complaints that could, in turn, lead to a declaration of failure of elections in that area.

Causes of an over-vote?

When an over-vote happens, none of the votes cast for that particular position will be counted. This would be the case when a ballot has more marks than the number required for a particular contest, which is usually 1 for most positions, 12 for senators, 6 or 8 for provincial board members, and so on. 

What can cause an over-vote? There are several reasons:

One of the advantages of an automated election system is that there is now access to an unprecedented level of detail that has not been available before. This includes the number of over-votes per precinct that are made available to accredited media organizations and election watchdogs.

Provincial over-voting rates

To be able to compare over-voting rates across provinces and the two automated elections, the two national positions that were common to both elections were selected: the party-list representative and the senators.

Top 3 over-voting provinces in 2010

Top 3 over-voting provinces in 2013


Going by province, Negros Occidental consistently appeared on the top of the ranking for top incidence rates of over-voting in both elections. In 2013, the Philippine Star reported that Negros Occidental had 5 ballot boxes sent to the Comelec after the random manual audit (RMA) found variances.

The national over-voting rate for the position of senator was 1.53% in 2010 and 2.14% in 2013. For party-list representative, it was much higher, at 3.38% and 8.86% in 2010 and 2013, respectively. This translates to almost 1.2 million voters in 2010 and almost 2.8 million voters in 2013.

Over-voting precincts

Having established the national over-voting rates, we don’t expect a precinct to then deviate by a large margin from that.


The 2010 automated elections had much less precincts encountering over-voting, with less than 1% of the precincts encountering more than 10% over-voting. In 2013, the number exploded to more than 30% of precincts.

There were 6 precincts that had more than half or 50% of its ballots considered as over-voting for the party-list position in 2010. This number jumped to 104 in 2013.

One of the 6 precincts in 2010 was clustered precinct 50 in Barangay Maliksi III in Bacoor, Cavite. 92% (513 of 557) of its valid ballots were not counted due to over-voting, for both senator and party-list positions. A precinct in Pantukan, Compostela Valley similarly had 74% and 73% over-voting for the senator and party-list positions, respectively. For both of these precincts, the president and vice-president positions also had the same rates of over-voting but had less than 5% for other positions which appeared on the other side of the physical ballot.

The other 4 precincts only registered high over-voting for the party-list position but had less than 2% over-voting for the senator position. Only the over-voting in the precincts in Bacoor and Pantukan could then be conclusively attributed to the vertical-line problem mentioned earlier. Interestingly, in 2013, Bacoor did not have any of its results transmitted to the transparency server.

Of the 104 precincts in 2013 with more than 50% over-voting for the partylist position, 27 precincts also had more than 50% over-voting for the position of senator. More than half of the 27 were in cities.

One of these 27 precincts is a clustered precinct in Mariano Ponce Elementary School in Tondo, Manila where 78% and 71% of its ballots were considered as having over-voted for the positions of party-list representative and senator, respectively. This could not be explained by voter error alone. There were 3 precincts in Quezon City and one in Mandaluyong.

Maliksi vs Saquilayan

In the 2010 elections, Homer Saquilayan was declared winner for the position of mayor of Imus, Cavite. Emmanuel Maliksi, who lost by 8,499 votes, filed an election protest with the Regional Trial Court of Imus, alleging instances of over-voting that were not registered as such by the PCOS machines.

The RTC agreed with Maliksi and declared him winner in its September 2011 decision, invalidating 7,758 votes of Saquilayan as over-votes and appreciating an additional 1,406 votes for Maliksi.

Saquilayan filed an appeal with the Comelec. The Comelec deemed the physical ballot

deeming the physical ballots as tampered and  that were used by the RTC decision as basis as tampered, opened up the digital images of the ballots that were recorded by the PCOS machines. The Comelec ruled in August 2012 that there were almost no over-voting for most precincts and that Saquilayan won by 8,429 votes over Maliksi.

The Supreme Court under Chief Justice Maria Lourdes Sereno issued a temporary restraining order (TRO) that stopped the Comelec from enforcing its decision to reinstate Saquilayan.

Less than two months before the succeeding election, the Supreme Court voted 8-7 to uphold the Comelec decision. A month later, the SC reversed its decision, citing the need for due process, and allowed Maliksi to stay in power.

Importance of the Random Manual Audit 

Random Manual Audits are useful for checking instances of the voting machines not working as expected. The Comelec, according to Vera Files, announced tripling the number of precincts that will be audited.

The 2016 General Instructions for the conduct of the Random Manual Audit provides for specific instructions to record instances of over-voting. This is done prior to the reading of votes cast. It also specifies that over-voting in any particular position will not invalidate the entire ballot.

The final report of the Random Manual Audit in 2013 showed that the PCOS machines in 2013 were more accurate than in 2010. The audits showed that machines registered 99.975% and 99.6% accuracy in 2013 and 2010, respectively. The law mandates an accuracy of 99.995%.

Voter vigilance

It is expected that there should be less incidences of undetected over-voting with the vote receipts mandated by the Supreme Court. In the 2010 and 2013 elections, the voters were unable to check if their votes were read correctly.

The Comelec advises the public that if they encounter any problem in voting, the proper way of filing complaints is to have these noted by election inspectors in their minutes, such as when the vote counting machines incorrectly recorded their votes as over-votes.

Lente advises voters to immediately check their ballot if there are any markings on it. It is possible for these markings to remain unspotted without voters deliberately looking at the ballots. – Rappler.com