Constitutional Court Backs QR Codes, Splits on Barcodes
Thailand's Constitutional Court unanimously upheld QR codes on ballots and narrowly approved barcodes in an 8-1 decision, finding both security measures protect against fraud without breaching ballot secrecy if proper procedures are followe
On September 28, 2025, the Constitutional Court issued a unanimous ruling upholding the constitutionality of QR codes on ballot papers, and an 8–1 majority decision backing the use of barcodes. The court was addressing 22 complaints referred by the Ombudsman under Section 213 of the Constitution regarding the Election Commission's use of both QR codes and barcodes on ballots in the February 8, 2025 general election, which critics claimed could breach ballot secrecy and constitutional standards.
The court found that the Election Commission's duty under Section 224(2) of the Constitution includes controlling and ensuring elections are conducted fairly and preventing electoral fraud such as vote-buying and undue influence. The court determined that ballot secrecy under Sections 84(2) and 85(1) must be balanced with fair election oversight.
Regarding QR codes, the court found that QR code identifiers on ballots cannot be linked back to identify individual voters, and therefore pose no constitutional problem. The codes serve only to track and manage ballot distribution across voting precincts and units.
For barcodes, the court acknowledged that barcode identifiers can theoretically be traced back through ballot serial numbers and voter sequence numbers to determine which party received a vote. However, the court found that comprehensive ballot management procedures—from printing and allocation through transport, voting, counting, and storage—already protect against ballots being diverted between districts. The barcode system simply helps officials verify that ballots were distributed to the correct areas.
Crucially, the court found no actual evidence in the complaints or witness testimony that anyone had used the barcodes to connect ballots with individual voters' choices, thereby compromising secrecy. The complainants' allegations were therefore insufficient to sustain a constitutional violation claim.