Tire Maintenance Safety

A Guide to the Tire DOT Number

Tires deteriorate over time, so knowing the age of your tires is vital as this ensures road safety and a smooth driving experience. The DOT number on your tires is important for more than just identifying the manufacturer because it can also tell you when and where your tire was made. Here's what you need to know about the Tire DOT Number on your tires.

What is the Tire DOT Number?

The Tire DOT number is found on the sidewall of the tire and it contains the letters “DOT” followed by a series of 8-13 letters and/or numbers known as the DOT code (also known as the Tire Identification Number (TIN). The DOT code is generated by the Department of Transportation and identifies where the tire was manufactured, the size of the tire, the manufacturer code, and the week and year the tire was manufactured. This number is important when registering new tires with the manufacturer and when identifying tires in the event of a product recall.

How to read the Tire DOT number

Once you look at the sidewall of your dot tire date codes – there will be a code following the letters “DOT” for the Department of Transportation. This can range up to 13 characters which will give you the information you need to identify your tire and also identify the date of manufacture of your tires. 7-13-character tire date code The first group consists of 2-3 characters representing the manufacturing plant code. (NOTE: New laws stipulate that the factory code should be changed from a 2-letter to a 3-letter code.) This extra digit makes the DOT code a total of 13 characters. The second group consists of six letters that identify the tire size, tire type, or other important tire characteristics. The last four digits represent the manufacturing date. (DOT AF WD9E 0521) 05 indicates the tire was manufactured in the 5th week of the year. The 21 number indicates it was manufactured in 2021. The first two digits indicate the week the tire was manufactured. The last two digits indicate the year the tire was manufactured. Special note: All tires manufactured after April 13, 2025, must comply with the thirteen-character Tire DOT number code requirement.

What do the numbers mean?

Giving a closer look at your passenger, truck, trailer, or motorcycle tire dot date code will help you with the information about its manufacturing and how long it has been in storage. Tires are often used for months or years at a time, so the DOT code on the tire may not be for the year you bought the tire, keep this in mind once you buy a tire.

Why is the tire DOT date code important?

The DOT code also serves as the safety standards seal of the US Department of Transportation. It certifies that the manufacturer complies with US Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) safety standards.


The biggest reason for the Tire DOT number code is tracking for security purposes. Tire manufacturers know the codes provided for each tire model, so they can easily inspect the various tires an automaker has ordered or recommended by hundreds of dealers as OEM replacements. DOT codes are also a very useful tool for consumers affected by tire recalls.


SimpleTire delivers you protection when your tire fails as a result of a puncture, bruise or impact incurred while driving on maintained roads. Nails, glass, and potholes are the most common examples of tire damage that would fall under Tire Replacement Coverage. 3-year protection Replacement of up to 100% of the tire cost Up to $25 reimbursement for necessary repairs ($50 on commercial tires) Certain restrictions apply and terms and conditions must be met to be eligible for this coverage.

FAQs: How do I read dot tire date codes? You can read the dot tire date codes by breaking the set of numbers into two sections. The first two numbers indicate the week, while the last two indicate the year. When did dot tire date codes begin? Tire Identification Number (often called a DOT number) was directed by the United States Department of Transportation in 1971.

Ready to find the perfect tires?

Search By