Different types of ID symbologies

Infrared check on an ID during ID authentication

Last updated on March 19th, 2024 at 03:23 pm

What is a symbology?

ID symbologies are used to store information in an optical and machine-readable way. They create a unique, but consistent, way to store letters and numbers through a variation of symbols. One common application of symbologies is on IDs and passports, which can be quickly and accurately scanned using a special device. At IDScan.net, we specialize in a few ID symbologies in particular

  • PDF417 (used on US drivers’ licenses and state IDs)
  • MRZ TD1
  • MRZ TD3 (used on global passports)

There are also QR codes, which are typically used to direct customers to a website or form but are used on some identity documents such as medical marijuana cards, student ID cards, and visitor badges.

While there are many other types of symbologies and use cases for them, PDF417 and MRZ are the two most relevant to ID scanning, ID authentication, and age verification.

PDF417 (aka 2D barcodes)

Example of a PDF417 barcode

PDF stands for Portable Data File. A PDF417 is a 2D printed symbol with a very high data density, which allows for large amounts of text and data storage in a secure and inexpensive way. While the barcode itself is small, it is actually capable of storing all the information you can visually see on the front of an ID, and more.

It’s often used for storing information on IDs, such as driver’s licenses and government-issued IDs, as well as airline tickets, shipping labels, and concert tickets. The information can be easily read by most ID scanners, making it a popular choice for items that require quick and accurate data retrieval.

PDF417 is a symbology has data redundancy, which allows scanners to read it with a certain degree of damage. The PDF417 must be printed at a certain size depending on the amount of information being stored in it. While technically a photo file could be stored in this format, it would make the PDF417 too large for proper use on an ID card.

Common uses for PDF417 barcodes                                                                           

  • Driver’s License
  • Government ID’s
  • Airline Tickets
  • Train Tickets
  • Shipping Labels
  • Concert Tickets

Machine readable zones (MRZ)


MRZ stands for machine-readable zone, which means that MRZ symbologies help a reader quickly pick up the information from a piece of identification using a machine reader.

This is a series of letters, numbers, and symbols printed in a specific pattern, typically found on the bottom of passports and visas.

They are 2D codes that retain the same information that you see on the front of the document. To make these codes readable, they must be put in the correct, standardized font as well as the correct type size. The organization ICAO is the governing body which sets the standards for MRZ documents. MRZ typically include things like a country code, the ID number, and the expiration date. 

MRZs come in many different formats, but the most common are called TD1 and TD3.


TD1 is used when there is limited space on a document, so it is designed to fit in a smaller area. It uses three lines to encode the same information that TD3 encodes, but in a more condensed format.

Common use cases for MRZ TD1

  • Passport ID Cards


MRZ TD3, on the other hand, is used when there is more space available on the document. It uses two lines to encode the same information that TD1 encodes, but in a more spread-out format. This makes it easier to read for humans, as the characters are less crowded and easier to distinguish.


Common uses For MRZ TD3 

  • Visa Cards
  • Passport Booklets

MRZ codes are used for quickly and accurately reading a few key pieces of information from an ID or passport, such as a person’s name, nationality, and passport number. They help speed up the process of verifying a person’s identity at border crossings and other checkpoints. To read an MRZ symbology you will commonly search for a “passport scanner.” Handheld ID scanners and most flatbed ID scanners are capable of reading both PDF417 barcodes and MRZ.

QR codes

A QR code is a square two-dimensional barcode made up of smaller squares, rectangles, and dots. QR codes are used to provide a quick and easy way for people to access information or content, such as directing users to a website or a form. They are often used in advertising, business cards, and event tickets, as they allow people to quickly access more information about a product or event.

QR codes are typically not used for identification documentation because they lack data redundancy and security features. However, they are being used in the workflow for verification of mDLs and digital IDs in some states.

Symbology FAQ

Which ID symbology can store the most information?

A PDF417 can store much more information than an MRZ. Both can store more information than a QR code.

How do I know which ID symbologies a scanner can read?

Almost all commonly available ID scanners will be capable of scanning 2D barcodes (PDF417). If it markets itself as a driver’s license scanner, it can undoubtedly scan PDF417 barcodes.

What happens after the information is parsed from the symbology?

If you are using a software like VeriScan or Wizzforms, the information stored in the symbology will be auto-pulled into your system as text strings which can then be mapped to the appropriate fields.

Is RFID a symbology?

No. Symbologies are, by nature, a visual medium.

Is magstripe a symbology?

No. Magstripes do not store information visually, so they are not considered a symbology. They are also considered increasingly outdated for information storage, which is why they are being continued for use on identity documents.


Symbologies are useful for storing and retrieving information from IDs and passports. They are accurate, efficient, and secure, making them ideal for industries like airlines, law enforcement, and hospitality. Using a scanner reduces the risk of errors and provides an extra layer of security against tampering, alterations, or forgeries.