The Constitutional Court has accepted a petition asking it to rule on the legality of barcodes and QR codes printed on ballot papers for the latest general elections.

The Constitutional Court judges resolved, by 6 to 3 votes, to accept the petition, forwarded by the Ombudsman on behalf of the public, following complaints over the use of barcodes and QR codes on ballot papers in the 8 February general elections.

The case stemmed from 21 complaints, filed by members of the public and politicians, against the Election Commission of Thailand (ECT).

Barcodes and QR codes were used on the ballot papers for both constituency and party list MPs, giving rise to concerns about a violation of electoral confidentiality. When scanned, they yield unique one letter and eight digit codes for each ballot paper.

Members of the public expressed alarm that the numbers were traceable and could potentially reveal how individuals voted, infringing on their rights and freedoms to vote in secrecy.

Ballot codes link to ballot stubs, where voters are obligated sign their names. The stubs also have voters numbers from the lists of eligible voters in each constituency. This makes it possible to identify voter ballots and the MPs and parties they voted for.

As the Constitution stipulates that elections must be carried out by direct suffrage and secret ballot, complainants argued that the codes compromise ballot secrecy.

Complaints in the case were reviewed by the Ombudsman’s office which found grounds for concern and resolved to forward to the matter to the Constitutional Court on 10 March.

The Court’s ruling could provide a standard for ballot redesign in future elections. Moreover, if it rules that the barcodes and QR codes violated the Constitution, the election could be declared void.

The Court requires both the ECT and the Ombudsman to submit the evidence within 15 days. It has yet to schedule a date to deliver a verdict.