VIN 11th Digit: How to Read the Assembly Plant Code

The 11th character of a VIN tells you which plant built the vehicle. Federal rule 49 CFR 565.15 says that character "shall represent the plant of manufacture," but it does not hand out the codes; each manufacturer assigns its own. So an "A" on one brand means nothing about an "A" on another, and you can only read position 11 alongside the first three characters, the World Manufacturer Identifier. Where it earns its keep is in spotting a VIN that does not match the car: the plant code, the door-jamb label and the WMI should all tell the same story.

I pulled the regulation text from eCFR and ran three public example VINs through NHTSA's free vPIC decoder on Saturday, October 17, 2026. All three came back "VIN decoded clean," with a correct check digit, so they are real, valid VINs, not ones I made up.

What the regulation actually says

Section 565.15(d) defines positions 10 through 17 as the VIN's fourth section. The first of those, position 10, is the model year, which our 10th digit model year guide covers. The second, position 11, is the plant. Positions 12 through 17 are the production sequence number for a high-volume maker, and for passenger cars and light trucks the last five must be numbers. That leaves position 11 free to be a letter or a digit. Per section 565.13, every VIN character comes from a set that leaves out I, O and Q, so if you see an O in position 11, someone typed a zero wrong or the VIN is bad.

That is the whole federal rule on plants: one sentence. There is no national table that says "F means Kansas." I read the section looking for one, and honestly, it just is not there.

Three real decodes from vPIC

Here is what vPIC's DecodeVinValues endpoint returned for each VIN, with the 11th character in bold:

• 1HGCM82633A004352: 2003 Honda Accord EX-V6 coupe. Position 10 is 3 for 2003, and position 11, A, decodes to Marysville, Ohio. vPIC left the plant company field blank.
• 1G1ZT53826F109149: 2006 Chevrolet Malibu LT sedan. Position 11, F, decodes to Kansas City, Kansas, with the plant name listed as Fairfax Assembly.
• 1M8GDM9AXKP042788: 1989 Motor Coach Industries 102C3 intercity bus. Position 11, P, decodes to Pembina, North Dakota.

Notice the Malibu. The code is F, the city is Kansas City and the plant name is Fairfax Assembly, so nothing about the letter hints at the location. Guessing a plant from the letter gets you nowhere. You need the maker's table, or a decoder that has it.

Why the plant code matters to a used buyer

The practical use is cross-checking. Under 49 CFR 567.4, the certification label on the driver's door edge, hinge pillar or latch post must show the name of the actual assembler after "Manufactured By" or "Mfd By," plus the month and year work was finished at the place of main assembly. So you have three things that should agree: the WMI, the plant decoded from position 11, and the assembler and build date on that sticker. If the dash VIN decodes to an Ohio plant and the door label names a company in another country, stop and find out why.

Sometimes the answer is innocent, like a replaced door with a missing label. Sometimes it is a cloned VIN, where a stolen car wears the identity of a legal one, and if the donor VIN came from a car built at a different plant, position 11 can give it away. Our VIN cloning guide walks through the dash plate, door label and title check. A bad character anywhere, including position 11, also throws off the check digit, which our check digit explainer shows how to compute.

The same logic applies to recalls. A recall lookup by full VIN checks that exact car, while a search by model and year only tells you a recall exists for some of them. So run all 17 characters, not just "2018 Civic."

What position 11 will not tell you

It does not tell you the brand, model or engine; positions 1 to 8 do that, starting with the WMI in our WMI explainer. It also does not tell you the car's history. A Marysville Accord can have three owners, a flood claim and a rolled odometer, and the plant code will read exactly the same. vPIC also has gaps, as the blank Honda plant company field shows, so a decoder that returns nothing for position 11 is not proof of a fake VIN by itself. Brand-specific pages like our Ford VIN decoder go further into one maker's codes.

Check the history once the VIN checks out

When the plant, label and WMI agree, run the title through NMVTIS and pull a history report on the full VIN yourself. A seller's PDF is a weak substitute; editing one VIN character in it takes no skill. CarVins is a licensed CARFAX and AutoCheck reseller, not affiliated with CARFAX, AutoCheck or Experian, and in mid October 2026 a report ran about $5.50 for guests, $4.50 for members or around $6.75 for both brands, compared with roughly $39.99 to $44.99 direct. Confirm at checkout, since our prices get adjusted now and then.

Sources

• eCFR: 49 CFR 565.15, VIN content requirements
• eCFR: 49 CFR 565.13, VIN general requirements
• eCFR: 49 CFR 567.4, certification label
• NHTSA vPIC API
• NMVTIS