The Constitutional Court is due to deliver its ruling on Monday on whether the use of barcodes and QR codes on ballot papers in the Feb 8 general election breached the constitutional requirement for voting to be secret.
The case was brought to the court through the Ombudsman which received 22 complaints over the Election Commission’s decision to use the codes on ballot papers.
Those codes could make it possible to trace ballots and identify voters, meaning the election may not have been conducted by secret ballot as required by the constitution.
After hearing witnesses and examining the evidence, the court set out the issues to be considered and scheduled a vote, with the ruling due at 2pm.
Three scenarios
Legal scholar Manit Jumpa, a lecturer at Chulalongkorn University’s law faculty, said the purpose of secret voting is to protect voters’ freedom to choose without others knowing how they vote.
There are three possible outcomes.
The first would be to rule that the use of barcodes does not violate the principle of secret voting. In that case, the petition would be dismissed and the matter would end there.
The second would be to find that the barcodes affected the secrecy of the election because ballots could potentially be traced after voting. The court could draw a comparison with the 2006 election, when polling booths were positioned in a way that allowed people outside to see how voters marked their ballots.
If the court rules that the 2026 election is invalid, a new election would have to be held. The consequences would extend beyond parliament, as the House and the government formed as a result of the election would also be affected, he said.
The third possibility would be for the court to find that using barcodes on ballots could potentially be used to trace voters, but there is no evidence that such tracing actually occurred.
The election would not be declared invalid. Instead, the EC would not be able to use barcodes on ballot papers in future elections unless the law is amended to make their use clear, he said.
Mr Manit said there was no public information before the election indicating the ballot papers would carry barcodes, and there is no evidence that voters are concerned their votes could be traced before going to the polls.
“The fact the possibility of tracing ballots only became a concern after the election could be an important consideration.
“However, there is no evidence that ballots were actually traced back to individual voters. The election could therefore still be considered to have been conducted freely and fairly,” he said.
He said this distinguishes the case from the earlier election, when polling booths were turned to face outwards.
At that time voters had only two party choices, or the option of not voting for any candidate, and people outside the booths could potentially see where a voter marked the ballot and determine how they voted.
A question of intent
Mr Manit said the EC confirmed the barcodes were introduced for the purpose of checking allegations of electoral fraud.
If the court’s examination found ballot boxes had been handled and stored under strict procedures, the decision to use barcodes could be viewed as an administrative decision made in good faith, Mr Manit said.
“There is also no evidence the EC intended to use information obtained from the codes to benefit a particular party.
“Claims that access to such information could give a party an advantage by showing where its supporters were located remain a possibility rather than an established fact,” he said.
Even if the court eventually finds the use of barcodes affected the secrecy of voting, this would not automatically mean the EC members committed an offence by performing their duties unlawfully, Mr Manit said.
The facts available at this stage may still not be sufficient to invalidate the election, he noted.
He said the EC had not used barcodes on ballot papers in the most recent local elections, as far as he was aware.
If the commission still considers barcodes necessary for checking electoral fraud in future, the law should be amended to make clear that their use does not breach the secrecy of voting, he said.
He cited a provision allowing voters with disabilities who cannot mark their own ballots to receive assistance. Such assistance is permitted under the law without being considered a breach of the secrecy of the vote.
Rangsit University’s political scientist Wanwichit Boonprong said the case is unlikely to have an immediate impact on the government.
In practice, there is still no evidence that the barcodes can be used to trace a ballot back to an individual voter and identify which candidate or party they supported.
Once ballots are mixed with millions of others, matching an individual ballot with a particular voter would be difficult unless there is evidence that authorities or another person have access to information that could identify voters, he said.
Mr Wanwichit said this is a political science assessment, while the interpretation of the law and the final consequences of the case remain matters for the court.
Former Democrat MP Thepthai Senapong offered a different view.
He compared the case with two previous elections that were declared invalid in 2006 and 2014.
In 2006, the court ruled the election invalid after polling booths were positioned in a way that compromised voting secrecy. The election had been held on April 2, 2006, and the court issued its ruling on May 8, taking 36 days.
In 2014, the election was held on Feb 2 but could not take place simultaneously nationwide after protesters blocked 28 polling stations. The court ruled the election invalid on March 21, 47 days after voting day.
As for the new case, the court will rule on Monday, seven months and 20 days after the election.
Mr Thepthai said in his view, the 2026 election presents the clearest case of a possible breach of voting secrecy when compared with the two previous elections.
However, the final decision rests with the court, he added.
Beyond the ruling
The case also has wider political significance.
The Senate election case has long been accompanied by claims the EC acted in the government’s interests.
Whatever the court decides, the ruling could be used to reinforce claims that the political system is working in favour of those in power.
The coming no-confidence debate and speculation about a possible cabinet reshuffle, including the possibility of Klatham joining the governing coalition, are adding to the ongoing uncertainty.
If divisions within the governing coalition deepen before the no-confidence debate, the government could come under pressure to dissolve parliament and call a new election.