What the Ontario Driver's License Number Tells You
Your Ontario driver's license number is a 15-character code printed on the front of your card. It is not random — each part of the number encodes information about you, including your name, date of birth, and sex. Understanding the format helps you verify your license is correct when you receive it, and it is useful when you need to provide your license number over the phone or online.
The format has remained the same since Ontario switched to the current license design. Whether you hold a G, G2, M, M2, or any other class of license, the number follows this same structure.
Key Takeaways
- Ontario driver's license numbers are 15 characters long and encode your surname, first name, date of birth, and sex.
- The first five characters are the first five letters of your surname, padded with numbers if your surname is shorter than five letters.
- Characters 6 through 9 are derived from your first name and date of birth using a specific algorithm.
- Characters 10 through 13 are your date of birth in YYMMDD format (year, month, day).
- Characters 14 and 15 are a check digit and a sex identifier (0 for female, 5 for male).
Breaking Down the 15-Character Format
The Ontario license number divides into five distinct sections, each serving a specific purpose. Learning what each section represents makes it easier to spot errors on your card or understand what information is embedded in your number.
Here is how a sample license number breaks down. If your number is SMITH123456789, the structure is:
| Position | Characters | What It Represents | Example |
|---|---|---|---|
| 1–5 | First five characters | First five letters of your surname (padded with numbers if shorter) | SMITH |
| 6–9 | Four characters | Derived from first name and date of birth | 1234 |
| 10–13 | Four characters | Your date of birth in YYMMDD format | 5678 |
| 14 | One character | Check digit (validates the number) | 9 |
| 15 | One character | Sex identifier: 0 for female, 5 for male | 0 |
The check digit in position 14 is calculated using a mathematical formula applied to the other characters. It exists so that ServiceOntario and other systems can detect if a license number has been mistyped or altered.
How Your Surname Encodes Into the First Five Characters
The first five positions always contain your surname. If your surname has five or more letters, the first five letters are used as-is. If your surname is shorter than five letters, the remaining positions are filled with numbers starting from 0.
For example, if your surname is Lee, the first five characters would be LEE00. If your surname is O'Brien, the apostrophe is typically ignored, so it becomes OBRIE. Hyphens in surnames are also usually ignored during encoding.
If your surname contains accented characters (such as é or ñ), ServiceOntario converts them to their unaccented equivalents (e and n) before encoding. This is important to know if you are checking your license number against your legal name.
How Your First Name and Birth Date Encode Into Characters 6–9
Characters 6 through 9 are generated using a formula that combines information from your first name and your date of birth. This section is not straightforward your first name spelled out — it is a coded result. The exact algorithm is proprietary to ServiceOntario, but the outcome is always a four-digit or four-character string.
This encoding means that two people with the same surname and date of birth but different first names will have different license numbers. It also means that if you change your first name legally, your license number will change when you renew or update your license.
Reading Your Date of Birth From Positions 10–13
Positions 10 through 13 contain your date of birth in YYMMDD format: two digits for year, two for month, and two for day. For example, if you were born on March 15, 1985, this section would read 8503 (85 for 1985, 03 for March, 15 for the day — though the day is split across positions 12 and 13).
The year is encoded as the last two digits only. This means someone born in 1985 and someone born in 2085 would have the same year digits (85). In practice, ServiceOntario interprets two-digit years using a cutoff: years 00–29 are read as 2000–2029, and years 30–99 are read as 1930–1999. This system will need updating around 2030.
If you are checking your license number and you know your birth date, you can verify that positions 10–13 match your month and day. This is a quick way to spot if your license was issued with incorrect personal information.
Understanding the Check Digit and Sex Identifier
Position 14 is the check digit, a single character calculated from all the other positions using a mathematical algorithm. When ServiceOntario or a police officer scans your license, the system recalculates this digit. If it does not match, the system flags the number as invalid. This protects against typos and fraud.
Position 15 is the sex identifier: 0 for female and 5 for male. This is a single digit that appears at the very end of your license number. If you have updated your sex designation with ServiceOntario, this digit will reflect that change when you renew your license.
What to Do If Your License Number Looks Wrong
If you receive a new license and the number does not match the format described here, or if the date of birth section does not align with your actual birth date, contact ServiceOntario when ready. Errors in encoding can happen during the process process, and correcting them early prevents problems when you need to use your license.
You can reach ServiceOntario by phone at 1-800-387-3445 or visit a ServiceOntario office in person. Bring your license and a piece of government-issued photo identification. If the error is confirmed, ServiceOntario will issue a replacement license at no charge.
Do not assume the number is wrong if it straightforward looks unfamiliar. The encoding system is designed to be opaque to the average reader — your license number is not meant to be straightforward to decode by eye. If you are unsure whether your number is correct, use the date of birth section (positions 10–13) as a reference point. That section should always match your actual birth date.
Frequently Asked Questions
Can I request a specific license number?
No. ServiceOntario generates your license number automatically based on your personal information. You cannot choose or customize it. The number is assigned when your license is first issued and remains the same throughout your life, even if you renew your license multiple times — unless you change your name or sex designation.
What happens to my license number if I change my name?
Your license number will change. When you legally change your surname or first name and update your license with ServiceOntario, a new number is generated based on your new name. You will receive a new physical card with the new number printed on it.
Why does my license number have letters in some positions?
The first five positions always contain letters (your surname). Positions 6–9 may contain letters or numbers depending on your first name and the encoding algorithm. Positions 10–15 are always numbers. If you see letters outside the first five positions, double-check that you are reading the number correctly — the font on the license can sometimes make numbers look like letters.
Is my license number the same as my driver's license number in other provinces?
No. Each province and territory in Canada uses its own license number format. If you move to another province and obtain a license there, you will receive a completely different number. Ontario's format is unique to Ontario.
Can I use my license number to verify my identity online?
Your license number alone is not sufficient for identity verification. Most online systems that ask for your license number also require your date of birth, address, or other personal information. Never share your full license number with unknown websites or callers claiming to represent ServiceOntario.