Incomplete DOT Code: Why the Tire Date May Be Missing
Learn why one tire sidewall may show a partial TIN without the 4-digit date code, how to locate the complete code, and what to decode.
Quick answer
A DOT marking without the final four-digit date code may be a partial Tire Identification Number. For many light-vehicle radial tires, federal labeling rules place the complete TIN on one sidewall and permit a partial TIN without the date code on the other. Inspect the opposite sidewall or ask a tire professional to locate it safely.
Key points
- The four-digit date code is the final group of the complete TIN.
- The visible sidewall may carry a permitted partial TIN with no date.
- Do not infer a manufacture date from the plant or manufacturer code.
- Record the complete TIN for recall and registration purposesânot only the date code.
What âincompleteâ usually means
The letters DOT can be followed by several groups of letters and numbers. Under current 49 CFR § 574.5, the TIN for a new tire contains a plant code, manufacturerâs code, and a final four-digit date code. The date code identifies manufacture week and year only.
FMVSS No. 139 contains sidewall-placement rules for covered light-vehicle radial tires. It requires the full TIN on the intended outboard sidewall and permits either a full or partial TIN on the other sidewall; the partial version can omit the date code. Directional or asymmetric mounting can therefore leave the complete code facing inward.
How to find the complete code safely
Start without crawling beneath an unsupported vehicle or trying to remove a wheel yourself.
- Photograph the visible DOT marking so you can compare both sides.
- Look for a final group of four digits, often visually separated from earlier characters.
- Turn the steering wheel only if the vehicle is parked safely and the ownerâs manual permits the inspection approach.
- For an inward-facing code that cannot be seen safely, ask a tire shop to record the complete TIN.
- Check every tire separately; manufacture dates and TINs can differ on the same vehicle.
What belongs in the decoder
Our date decoder accepts only the final four digits, such as 1524. The first two digits identify the manufacturing week and the last two identify the year. The rest of the TIN does not make the four-digit date more precise.
Do not enter the plant code, tire size, a molded part number, or a random four-digit marking. A plausible-looking number elsewhere on the sidewall is not necessarily a date code. Confirm that it is the final group of the complete TIN.
Why you should save the full TIN
The four-digit date is useful for age context, but recall identification may require more of the TIN. When buying or inspecting tires, save clear photos of the complete codes and keep purchase records. This makes it easier to compare a recall population and document warranty or registration questions.
Frequently asked questions
Why does my DOT code have no date?
You may be looking at a partial TIN on the opposite sidewall from the complete code. The full TINâs final group contains the four-digit week-and-year date.
Is the date code always four digits?
For tires manufactured since 2000, the date code uses four digits. Much older tires may use a legacy three-digit format that does not identify the decade unambiguously.
Can the date code be on the inside sidewall?
Yes. Depending on tire design and mounting orientation, the sidewall carrying the complete TIN may face inward.
Can I decode a partial TIN?
You can interpret visible components such as a plant code when verified, but a partial TIN without the final four digits does not reveal the manufacture date.
Primary sources
We use US government regulations and consumer guidance for factual claims. Links open the source publisher.
- 49 CFR § 574.5 â
Current TIN content, symbol, and four-digit date-code requirements.
- 49 CFR § 571.139 â
Full and partial TIN placement rules for covered radial tires.
- NHTSA TireWise â
Consumer tire sidewall and date-code guidance.