How to Make Sense of the Barcodes on Your Ballot

How to Make Sense of the Barcodes on Your Ballot

Barcodes store information such as the election date and year, the county that produced the ballot, and the voters' selections.

The way ballots are created and counted has been modernized significantly since the passage of the federal Help America Vote Act of 2002.

Accuracy and reliability problems with older equipment, including punch card and lever machines, increased interest in ballot-counting equipment among legislators at the state and federal levels. Hand-counting ballots at scale was time-consuming, expensive and often inaccurate, so machine counting was considered the path forward. The federal government established voluntary voting system guidelines under the newly created Election Assistance Commission, and many states adopted federal standards, in some cases adding their own requirements for voting machines. These standards have been updated over time to adjust to evolving technology. Today's voting systems tabulate paper ballots and use barcodes for a variety of reasons.

Barcodes store information such as the election date and year and the county that produced the ballot. They also tell the voting machine where to look for voter selections on the ballot. The machine-readable format can be read by software programs and then translated for human viewing.

Commonly Used Barcodes

1D Barcodes

This is the type of barcode most people are familiar with from the grocery store checkout. Technically known as one-dimensional, or 1D, barcodes, they have been used for decades to store information. They typically consist of a series of vertical lines that vary in width.

QR Code

Originally created for labeling automotive parts, a quick response, or QR, code is a two-dimensional barcode that's familiar to anyone who's used a cellphone to access a restaurant menu. QR codes have been widely adopted because they can store more information than traditional barcodes.

Timing Mark

This type of barcode may be less familiar. Timing marks appear much simpler than other barcodes and consist of blocks or lines around the perimeter of a ballot.

In recent years, some have expressed concern about the use of barcodes to store voter selections on ballots, since voters cannot verify the contents of the barcodes with their eyes alone. Some election officials publish tables that allow voters to verify barcode contents with their smartphone and ensure that the barcode in use is based on an open standard.

Additionally, some security researchers have expressed concern that more complex barcodes could be used to attack election systems by including malicious instructions, though this problem has not been identified in real-world conditions.

While no state has fully eliminated barcodes on ballots, some states have moved away from their use as a tool to store vote selections. The Colorado secretary of state announced in 2019 that the state would stop using ballots with QR codes. Implementing the ban required changes to Colorado election rules and equipment upgrades for all Colorado counties, a process that took multiple years to complete. More recently, Georgia prohibited (SB 189) the use of barcodes to store voter selections on ballots. The July 1, 2026, implementation date required in the bill is approaching but equipment updates have not yet been made.

The Election Assistance Commission's Voluntary Voting System Guidelines, version 2.0, adopted in early 2021, do not prohibit the use of barcodes to store voter selections, but the commission is considering a ban on QR codes for future versions.

Luke Belant is a project manager in NCSL's Elections and Redistricting Program.