What Your Ontario License Number Actually Tells You

Your Ontario driver's license number is a 16-character code printed on the front of your card. It is not random — each part of it encodes information about you: your name, your date of birth, and your sex. Learning to read it takes about a minute, and it helps you understand what information the province stores about you and how to spot a fake or altered license.

The format is always the same. The first five characters are letters derived from your last name and first name. The next six characters are numbers that represent your date of birth. The next two characters are a sequence number and a check digit. The final three characters are a code that identifies the license issuer. Once you know what each section means, you can decode any Ontario license in seconds.

Key Takeaways

  • The first five characters of your license number come from your last name and first name, using a specific algorithm that the province publishes.
  • Characters 6 through 11 encode your birth year, birth month, and birth day in a compressed format that looks like a six-digit number.
  • Character 12 is a sequence number that increments if you renew your license or if someone else has the same name and birth date.
  • Character 13 is a check digit used to detect errors or tampering when the license is scanned.
  • The last three characters identify which ServiceOntario office issued your license.

Characters 1–5: Your Name Code

The first five letters of your license number come from your surname and given name, but not in the way you might expect. Ontario does not straightforward take the first letters of each. Instead, it uses a standardized algorithm called the Soundex code, which groups names that sound alike even if they are spelled differently.

The first character is always the first letter of your last name. The next four characters are numbers (0–6) that represent the consonant sounds in the rest of your last name and your first name combined. Vowels and certain consonants (W, H, Y) are ignored. If your name is short or has few consonants, the remaining positions are filled with zeros.

For example, if your last name is Smith and your first name is John, the code begins with S (first letter of Smith), then adds digits based on the sounds in "mith" and "john". You can verify your own code by looking at your license and checking it against the Soundex algorithm published on the ServiceOntario website.

Characters 6–11: Your Date of Birth

The next six digits encode your date of birth in the format YYMMDD — that is, year, month, and day. However, the year is compressed into two digits, so you need to know the rule for interpreting it. If the first digit of the year code is 0–9, it represents 1900–1999. If it is A–Z, it represents 2000–2099.

For example, if characters 6–7 are "75", you were born in 1975. If characters 6–7 are "A5", you were born in 2005. Characters 8–9 are your birth month (01–12), and characters 10–11 are your birth day (01–31). This section is straightforward once you remember the year rule.

Character 12: Your Sequence Number

Character 12 is a single digit (0–9) that increments each time you renew your license or each time the province issues a new license to someone with an identical name and birth date. On your first license, this digit is usually 0. When you renew, it becomes 1, then 2, and so on.

This number helps the province track how many times you have held a license and ensures that each license has a unique identifier even if two people share the same name and birth date.

Character 13: The Check Digit

Character 13 is a check digit — a single number calculated from all the other characters in your license number using a mathematical formula. It serves as a safeguard: when your license is scanned at a police stop or at a border crossing, the scanner recalculates the check digit and compares it to the one printed on your card. If they do not match, the scanner flags the license as potentially altered or counterfeit.

You do not need to calculate this yourself. It is there to protect you and to help authorities verify that your license is genuine.

Characters 14–16: The Issuing Office Code

The final three characters identify which ServiceOntario office issued your license. Each office has a unique three-digit code. For example, code 001 might represent the Toronto office, while 050 might represent an Ottawa office. These codes are not published in a public directory, but they allow the province to track where licenses are issued and to investigate patterns of fraud or error.

If you renew your license at a different ServiceOntario office, this code will change on your new card.

Why This Matters When You Renew or Replace Your License

When you renew your Ontario driver's license, your license number changes. The sequence number (character 12) increments, and the issuing office code (characters 14–16) may change if you renew at a different location. Your name code, date of birth, and check digit remain the same because they are derived from information about you that does not change.

If you lose your license and need a replacement, ServiceOntario will issue a new card with a new license number. The sequence number will increment again. This is why your license number is not the same as your driver's license record number — the record number stays the same throughout your life, but your license number changes with each new card.

Frequently Asked Questions

Can I use my license number to find out someone else's date of birth?

Yes, if you know how to read the format. Characters 6–11 encode the date of birth in YYMMDD format, so you can extract the birth year, month, and day from any Ontario license number. This is why protecting your license number is important — it reveals personal information.

What does it mean if my license number has a letter in the year section?

A letter in characters 6–7 means you were born in the 2000s. The letters A–Z represent years 2000–2099. For example, "A0" means 2000, "B5" means 2015, and "C9" means 2029. This system allows the province to distinguish between someone born in 1975 and someone born in 2075.

Does my license number change if I change my name?

Yes. If you legally change your name, your license number will change because the first five characters are derived from your name. When you renew or replace your license after a name change, ServiceOntario will issue a new license number based on your new name.

Why do some people have the same license number?

Two people cannot have the exact same 16-character license number. However, two people with the same name and birth date will have the same first 11 characters. The sequence number (character 12) will be different — one person might have a 0 and the other a 1 — to keep the full number unique.

Can I verify my license number is correct?

You can check that your license number follows the correct format by comparing it to the rules described here. However, verifying that the check digit is mathematically correct requires the formula that ServiceOntario uses, which is not publicly documented. If you believe your license number is wrong, contact ServiceOntario directly.