What a Tire Identification Number Is and Where to Find It

A Tire Identification Number (TIN), also called a DOT number, is a unique code stamped into the sidewall of every tire sold in the United States. It identifies the tire's manufacturer, the plant where it was made, the week and year of production, and the tire size and type. The number starts with the letters "DOT" followed by a series of numbers and letters, typically 8 to 13 characters long.

You'll find the TIN on the outer sidewall of your tire — the side you can see when the wheel is on your vehicle. Look for "DOT" followed by the code. On some tires, the full number wraps around the sidewall, so you may need to crouch down and look at different angles. The TIN is required by the Department of Transportation and is the only way to trace a tire back to its manufacturer and production date.

The TIN matters because it's the identifier used in tire recalls, warranty claims, and when you need to prove when a tire was made. If a manufacturer discovers a safety defect, they use TINs to notify owners and track which vehicles are affected. It's also useful information if you're buying used tires or investigating why a tire failed.

Key Takeaways

  • The Tire Identification Number is a DOT code stamped on the tire's outer sidewall and is the only official way to identify when and where a tire was manufactured.
  • The last four digits of the TIN represent the week and year the tire was made, which determines whether it falls under a recall or warranty claim.
  • You can find recall information and check whether your tire is affected by searching the NHTSA website using your vehicle's VIN or the tire's TIN.
  • Used tire dealers and private sellers should provide the TIN so you can verify the tire's age and check for recalls before purchase.

How to Decode the Numbers and Letters

The TIN is divided into sections, each with a specific meaning. The first two characters are always "DOT," which certifies the tire meets Department of Transportation standards. The next two or three characters are the manufacturer's code — a unique identifier assigned to the company that made the tire. After that comes the tire size code, which tells you the width, aspect ratio, and wheel diameter.

The most important part for safety is the last four digits: the production date. The first two digits represent the week of the year (01 through 53), and the last two digits represent the year. For example, a TIN ending in "3523" means the tire was made in week 35 of 2023. This date is critical because tires degrade over time, even if they're not being used. Most tire manufacturers and safety experts recommend replacing tires that are 10 years old or older, regardless of tread depth.

Here's an example of a complete TIN: DOT M5A 437 3523. "DOT" is the certification, "M5A" is the manufacturer code, "437" is the tire size and type code, and "3523" is the production date (week 35, 2023). Not all TINs follow this exact format — some manufacturers use different numbering systems — but the last four digits always represent the week and year.

Why the Production Date Matters

The production date on your TIN is one of the most practical pieces of information you can extract. Tires are made of rubber and other materials that break down over time due to exposure to heat, UV light, and ozone, even if the tire is sitting in storage. A tire that looks fine on the outside may have internal damage that makes it unsafe to drive on, especially at highway speeds or in hot weather.

If you're buying used tires, the production date tells you how old they really are. A tire that looks like it has plenty of tread but was manufactured 8 or 9 years ago may not be a good deal. Conversely, a tire that's only 2 or 3 years old is likely to perform better and last longer, even if it has some visible wear. Always check the TIN before purchasing used tires, and ask the seller for the date if they don't provide it.

The production date is also used to determine whether a tire is covered under the manufacturer's warranty. Most tire warranties are limited to a certain number of years from the production date, not from the date you purchased it. If you buy a tire that was manufactured 5 years ago but is new to you, you may only have 5 years of warranty coverage remaining instead of the full warranty period.

How to Check for Recalls Using the TIN

The National Highway Traffic Safety Administration (NHTSA) maintains a database of all tire recalls. You can search for recalls in two ways: by your vehicle's VIN (Vehicle Identification Number) or by the tire's TIN. To search by TIN, visit the NHTSA website at safercar.gov and select the "Recalls" section. You'll need to enter the tire manufacturer's name and the TIN.

When you search, the database will show you whether that specific tire has been recalled and, if so, what the defect is and what you should do. Some recalls require you to stop driving the vehicle when ready; others allow you to continue driving until you can get the tire replaced. The NHTSA will also provide instructions on how to contact the manufacturer or a dealer to get a replacement or refund.

If a recall is issued after you've purchased your tires, the manufacturer is required to notify you if they have your contact information. However, not all tire buyers register their tires with the manufacturer, so checking the NHTSA database yourself is the most reliable way to stay informed. You can check as often as you want, and it's free.

Reading the TIN on Your Vehicle

To find your tire's TIN, start by locating the outer sidewall of one of your tires. The outer sidewall is the side facing away from the vehicle's body — the side you see when you look at the wheel from the outside. Look for the letters "DOT" printed in white or raised lettering. The full TIN should be printed right after "DOT."

If you can't find it on the first tire you check, try another tire. Sometimes the TIN is easier to read on one tire than another depending on how the tire is positioned and how much dirt or debris is on the sidewall. You may need to clean the sidewall with a damp cloth to see the numbers clearly. If you're checking all four tires, you may find that they have different TINs if they were manufactured at different times or by different plants.

Write down the TIN or take a photo of it for your records. This information is useful if you ever need to file a warranty claim, check for recalls, or investigate a tire failure. Keep the TIN in your vehicle's maintenance log or in a file with your insurance documents.

What to Do If You Can't Find or Read the TIN

If the TIN is worn, faded, or damaged to the point where you can't read it, you have a few options. First, try cleaning the sidewall thoroughly with soap and water, or use a soft brush to remove any buildup. Sometimes the numbers become visible once the dirt is removed. If the TIN is still illegible, you can contact the tire manufacturer directly with information about your tire — such as the size, tread pattern, and any other markings — and they may be able to help you identify it.

If you're unable to determine the TIN and you need to check for recalls or file a warranty claim, contact the tire retailer or the manufacturer's customer service line. Provide them with as much information as you have: the tire size (printed on the sidewall), the brand name, the tread pattern name if you know it, and approximately when you purchased it. They can often look up the tire in their system and provide you with the production date and recall information.

For safety reasons, if you cannot verify the age of a tire and you suspect it may be older than 10 years, consider replacing it. The cost of a new tire is less than the risk of a blowout or loss of traction on the road.

Frequently Asked Questions

Is the TIN the same as the tire serial number?

The TIN is sometimes called the serial number, but they're the same thing. The DOT number is the official identifier used by the Department of Transportation and tire manufacturers. Some people use the terms interchangeably, but "Tire Identification Number" and "DOT number" are the correct names.

Can I look up a tire's history using just the TIN?

The TIN tells you the manufacturer, plant, and production date, but it doesn't tell you the tire's ownership history or how it was used. You can use the TIN to check for recalls and to verify the tire's age, but you cannot see whether it was driven hard, stored improperly, or repaired. For used tires, inspect the tire visually and ask the seller about its history.

What does it mean if the TIN has letters instead of all numbers?

The manufacturer code and tire size code sections of the TIN include both letters and numbers. This is normal and varies by manufacturer. The production date at the end is always four digits (week and year), but the rest of the TIN can include letters. As long as the TIN starts with "DOT," it's a valid identifier.

Do I need to register my tires with the manufacturer using the TIN?

Registration is optional but recommended. If you register your tires with the manufacturer, they can contact you directly if a recall is issued. However, you can always check the NHTSA website yourself to see if your tires are affected by a recall, so registration is not required to stay informed.

How old is too old for a tire, and how do I know using the TIN?

Most experts recommend replacing tires that are 10 years old or older, even if the tread looks good. To find the age, look at the last four digits of the TIN. If the year is more than 10 years in the past, the tire should be replaced. For example, if today is 2024 and the TIN shows "2514" (week 25, 2014), the tire is 10 years old and should be replaced.