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Dec 9 2019

There’s a lot more to VIN numbers, the 17-digit string of numeric and alphanumeric characters found on vehicles, and the vehicle data behind them than you may expect. In fact, VINs can be quite complex.

We’ve put together an article highlighting some interesting facts about VINs, VIN decoding, and vehicle data that often come as a surprise to many of our end users. Perhaps some of these facts will help clarify questions you’ve had while working with VINs.

1. Most VIN decoders do not decode all 17 digits of a VIN

The majority of VIN decoders on the market do not actually decode all 17 digits of the VIN, as the build data required to do this is either unavailable or too expensive. Instead, most VIN decoders decode the VIN pattern made up of positions 1-8, 10, and 11. The remaining characters of the VIN are in position 9 (check digit) and positions 12-17 (serial number). The check digit is used for VIN validation and the serial number is what makes each VIN unique.

The VIN pattern is all that’s needed for identifying some basic vehicle details, such as year, make, model, engine type, and certain safety equipment. For a more detailed and precise decode, a comprehensive VIN decoding service, such as DataOne’s VIN decoder API, will be needed. Some businesses, such as dealers and dealer service providers, utilize 17-digit VIN decoding to obtain the highest level of detail possible, including vehicle color and installed optional equipment and packages, to better represent the vehicles they are selling.

2. Trim and transmission aren't always encoded in the VIN pattern

The information encoded in a VIN pattern may vary from one manufacturer to another. Although the NHTSA has required certain information to be encoded in the VIN, there is leeway within the vehicle descriptor section (VDS), positions 4-8, given that each vehicle is unique. As a result, there are some significant details, such as trim and/or transmission, that may be left out of the VIN pattern. Several manufacturers do encode trim consistently, including Honda and Subaru, however, there are still many manufacturers that do not. As for transmission, fortunately, it’s becoming easier to identify by default, as manual transmissions are less commonly used now.

Here are a few helpful resources on the topic:

3. Some RVs can have two VIN numbers, sometimes with different model years

There are a several different types of RVs, including Class A, B, and C motorhomes (drivable RVs) and various types of travel trailers (towable RVs), that are required to have a VIN.

With Class A, B, and C motorhomes, it’s possible to have two different VINs assigned - one by the RV or “coach” manufacturer and the other by the truck chassis (Class A), truck cab (Class C), or van cab (Class B) manufacturer.  It’s also possible that the chassis/cab could be manufactured the previous model year and the RV would have two different model years, often referred to as “multi-stage RVs”. This is common and doesn’t go against any regulations, as long as the chassis age does not exceed two years before completion of the motorhome, according to a Faegre Baker Daniels article. In fact, only a few states (including California) require dealers to disclose this information.

Given the complexity of motorhomes and lack of standardization for how these vehicles are identified, there isn’t a good way to build out a VIN decoding solution. However, towable RVs are a different story. Learn more about trailer VIN decoding here.

4. Not all VIN numbers are 17 digits long

The NHTSA has required all vehicles manufactured since 1981 be assigned a 17-digit VIN number. Prior to 1981, there was no VIN standard.  VIN formats, including length and encoded vehicle details, would vary across different manufacturers. Many foreign manufacturers would just assign engine numbers and serial numbers.

In the 1950s and 1960s, when VINs were created, they were typically 8-10 characters long (sometimes less).  The data encoded in these shorter VINS included vehicle series identity (model), model year, assembly plant, and a sequential production number. Some manufacturers, including Ford, Plymouth, and Studebaker, encoded engine type and in some cases body style. In the late 60s and early 70s, VIN numbers started to get a little longer (typically 13 characters) and more manufacturers started to encode engine type and body style.

With so much variability across manufacturers and how they identified their vehicles, a VIN decoding solution such as DataOne’s could not have existed prior to the standardization. Thankfully the 17-digit VIN standard has made it possible to identify certain data points consistently for all manufacturers, as well as easily verify the validity of a VIN.

5. VIN patterns can be reverse engineered

In situations where a user is required to submit a VIN but doesn’t have it handy, such as submitting an online insurance quote request, some VIN decoding solutions can reverse engineer a VIN pattern. In order to do so, certain vehicle details are required, including year, make, model, trim, body type, and drive type.

Reverse VIN engineering should only be used for this type of preliminary quoting process as it will not generate a full 17-digit VIN, only the VIN pattern. The full VIN is required for properly underwriting an insurance policy.

6. VIN standards are not the same world-wide

While vehicles destined for sale in the U.S. and Canada adhere to the NHTSA VIN standard, the rest of the world follows the ISO standard. The two standards are very similar, and both use the same World Manufacturer Identifier (WMI) format for positions 1-3. However, there are some differences. One of the major differences is that the NHTSA VIN standard uses a check digit in the 9th position to validate VINs, while the ISO standard extends their vehicle descriptor section (VDS) an extra character (positions 4-9).

Compare the two VIN standards with our handy NHTSA & ISO Standard Comparison infographic.

7. Every VIN encodes the country of manufacture

There is quite a bit of variability in what vehicle information can be identified by VIN number, especially across the two VIN standards (NHTSA and ISO). However, as mentioned in my previous point, the WMI is the same worldwide. Therefore, the country of manufacture (as well as the vehicle manufacturer) can always be identified by VIN. The NHTSA standard also includes the manufacturing plant.

8. VIN decoders require constant updating and maintenance

Though the logic and rules behind VIN decoding don’t change, VIN decoding providers constantly need to update their databases to decode the newest model years, mid-year model releases, and sometimes mid-year trim. Additionally, there are ongoing pricing updates, OEM compliance updates (ex. different branding requirements set forth by the manufacturer), and mid-year content updates (ex. optional equipment that has become standard) that are required to maintain a clean vehicle database.

9. Medium and heavy-duty truck VINs offer less detail than passenger/light-duty vehicles

Decoding medium and heavy-duty truck VINs is valuable for many businesses. However, the amount of information that can be obtained from medium and heavy-duty VINs is much more limited than the passenger/light-duty market, in large part due to the level of customization involved with these vehicles. The majority of medium-duty trucks are upfitted with a different body, which is not tied to the VIN, and heavy-duty trucks (tractor-trailers and straight trucks) and the trailers they haul both have their own VINs.

Learn more about VIN decoding outside the passenger/light-duty market in this article.

10. Model year is impossible to identify by VIN alone for some medium and heavy-duty trucks

The NHTSA requires vehicles with a GVWR of 10,000 lbs. or less (passenger and light-duty vehicles) to follow a certain standard for model year. This standard leverages position 7 in conjunction with the year code in position 10 to determine what year the vehicle was manufactured between 1980-2009 or 2010-2039.

Medium and heavy-duty vehicles do not have the same requirement and as a result can use the same VIN pattern for multiple years, which creates a problem in identifying model year. When a medium or heavy-duty vehicle model is manufactured for many years, within both year ranges (1980-2009 and 2010-2039), it’s impossible to determine what year the vehicle was manufactured by VIN alone.

11. VIN decoders do not tell the history of a vehicle

The information encoded in a VIN is what is installed at the time of manufacture and a VIN decoder tool simply decodes this information. Vehicle history data, such as accident damage reports, registration records, ownership transfers, etc., is tied to (but not encoded in) the VIN throughout the life of the vehicle, since the VIN is a unique identifier, like a human’s DNA.

A vehicle history provider, such as Carfax or Experian, receives vehicle history information from several different sources, including U.S. motor vehicle agencies, collision repair facilities, and insurance companies.  A consumer or dealer can then access the vehicle history by supplying the vehicle’s VIN or associated license plate number. As a result, many think that VIN decoding solutions can provide vehicle history data, but this information is not encoded in the VIN,  but rather tied to it.

Here’s an article on the differences between VIN decoders, VIN checks, and vehicle history reports for further detail.

12. Accessories, and some optional equipment/packages, are not encoded in a VIN unless installed at time of manufacture

Vehicle accessories are typically installed at either the port or the dealership, after the vehicle has been badged with a VIN (which occurs at the time of manufacture). This is also true for a good amount of optional equipment. As a result, this information will not be encoded in the VIN.


Although the 17-digit VIN is now standardized, there are still many variables to consider that make vehicle identification a little more challenging.

It’s important to understand the nuances of VINs and VIN decoding when deciding on a vehicle data solution, especially if your business requires a great deal of vehicle detail. We’d be happy to discuss your data­­ requirements and help you determine which solution will best fit your needs. 

Maybe you are just interested in learning more about VIN decoding. Check out our VIN Decoding 101 blog article series for a deeper dive.





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