Tire Date Code: How to Read It, Where to Find It and How Tire Shops Check Tire Age at Scale

Key takeaways

• The tire date code is the last four digits of the DOT number on the sidewall. The first two digits are the week, the last two are the year.
• “2421” means the tire was made in the 24th week of 2021.
• A three-digit date code means the tire was made before 2000.
• The full date code is often on only one sidewall, which may face inward once the tire is mounted.
• Tire shops check date codes for safety, recalls, warranty and resale. Typing them by hand is slow and error-prone; AI-enabled smartphone scanning captures them in a single photo.

What Is a Tire Date Code?

A tire date code is the four-digit number at the end of a tire’s DOT code that shows the week and year the tire was manufactured. It is part of the Tire Identification Number (TIN), which U.S. federal rules require on every tire sold in the United States.

The full DOT code starts with the letters “DOT” and runs to roughly 10–13 characters. Only the final four digits carry the date. Everything before them identifies the factory, the tire size and the manufacturer’s own batch or type code.

How to Read a Tire Date Code

Read the date code in two pairs: the first two digits are the week of the year (01–52), and the last two are the year.

A full DOT code breaks down into four parts:

1. Plant code (2–3 characters after “DOT”) – the factory that made the tire.
2. Size code (2 characters) – the tire size.
3. Manufacturer’s code (up to 4 characters, optional) – type, brand or batch details.
4. Date code (last 4 digits) – week and year of manufacture.

If the code ends in three digits, the tire was made before 2000. There is no reliable way to tell which year of the 1990s it was, and it should be treated as too old for service.

Where to Find the Date Code on a Tire

Look on the lower sidewall, near the rim, for a string that starts with “DOT”. The date code sits at the end of that string, often inside a small raised oval.

Three things make it harder to find than it should be:

• One-sided placement. The full code, including the date, is often molded on only one sidewall. If you see a DOT code with no four-digit ending, check the other side.
• Mounted tires. On a vehicle, the full code may face inward toward the suspension. You may need to turn the wheel or lift the vehicle.
• Black-on-black text. The characters are embossed rubber on rubber, with no colour contrast. Dirt, tire shine and wear make them harder to read, especially in a dim service bay.

How Old Is Too Old? Tire Age Guidelines

There is no single U.S. federal age limit for passenger tires. Most guidance comes from tire and vehicle manufacturers and it varies by brand.

Common industry practice is:

• Around 5 years: have tires inspected every year, even if tread looks fine.
• Around 6 years: several vehicle manufacturers advise replacement from this point.
• 10 years: widely treated as the outer limit, regardless of tread depth or appearance.

Rubber ages even when a tire sits unused in a warehouse or on a spare. Heat, sunlight and low inflation speed that up. Always follow the specific manufacturer’s guidance for the tire in front of you.

Why Tire Shops Check the Date Code on Every Tire

For a tire shop, dealership service lane or used-tire reseller, the date code is not trivia. It drives four everyday decisions:

1. Safety and liability. Selling or re-mounting an aged tire exposes the shop if that tire fails.
2. Recalls. Recalls are issued against specific DOT code ranges. Without the code on file, the shop cannot tell a customer whether their tires are affected.
3. Warranty and registration. Warranty eligibility and tire registration both depend on the TIN being recorded correctly at the point of sale.
4. Inventory and resale value. Older stock should sell first, and used or reconditioned tires are priced partly on age. A wrong date means a wrong price.

The common thread: every decision depends on the DOT code being captured accurately, for every tire, every time.

The Problem With Logging DOT Codes by Hand

Most shops still record DOT codes the slow way. A technician kneels, finds the code, reads embossed characters, and types or writes 10–13 characters per tire. A set of four means four times the effort, plus the inward-facing sidewall problem.

This creates predictable failures:

• Transposed characters. Look-alike characters such as 8 and B, or 0 and D, slip into records.
• Skipped tires. Under time pressure, technicians log one tire and assume the set matches.
• Records that don’t connect. Codes written on paper rarely reach the inventory, invoice or registration system.

Each of these breaks the chain that recalls, warranties and audits rely on.

How Smartphone DOT Scanning Works

AI-enabled DOT scanning replaces manual typing with a single photo. A technician points a smartphone or tablet at the sidewall, and the app reads the full DOT code  including the date code  and sends it straight into the shop’s system.

The Scanflow tire sidewall scanning SDK is built for exactly this surface: embossed, low-contrast, black-on-black text on a curved sidewall. It plugs into existing iOS and Android apps, so shops and software vendors add DOT capture to the tools technicians already use, without new hardware.

For aftermarket and retail teams, that means:

• Capture at intake, tire by tire, with the date code checked against the shop’s age policy on the spot.
• Recall and registration data recorded at the point of sale instead of retyped later.
• Inventory rotation based on real manufacture dates, not guesswork.
• Used and reconditioned tire grading with age captured in the same workflow as tread checks.

For a step-by-step look at the capture itself, see how to scan tire DOT numbers with a smartphone.