Harley-Davidson VIN Decoder: What Every Digit Means (Engine Codes, Model Codes, Year Codes)

Every Harley built since 1981 carries a 17-character VIN, and every one of those characters means something: where it was built, what engine is in it, what model it started life as, what year it is. If you're buying a used bike, ordering parts, or trying to figure out what somebody's chopper actually started out as, the VIN is where you start. Here's how to read one, character by character, using the code tables Harley files with the U.S. government (NHTSA).

Older bikes are a different animal. Pre-1981 Harleys don't have a 17-digit VIN at all, so we'll cover those separately at the bottom.

Where the VIN Is

On the frame: stamped into the right side of the steering head, and repeated on a sticker on the frame downtube or steering head. Your title and registration will have it too. The engine has its own number on the left side of the crankcase (below the front cylinder on most models). On a factory bike the last ten characters of the engine number match the last ten of the frame VIN. If they don't match, the engine's been swapped, and you'll want to know that before you hand over cash.

The 17-Character VIN, Broken Down

Take a 2018 Street Glide as the example:

1HD1KBM10JB612345

Positions 1–3: Manufacturer (WMI)

A 5HD bike isn't a problem, it just means it was built for an export market and came back to the States at some point. Parts are the same. Emissions and lighting equipment might not be.

Position 4: Weight Class

Position 7: Engine Codes

This is the one most people care about. The letter in position 7 tells you the engine family and displacement. Harley reuses letters across eras, so read it together with the model year in position 10. These are pulled straight from Harley's VIN filings with NHTSA.

1981–1999 (Shovelhead, Evolution, Ironhead, early Twin Cam)

2000–2016 (Twin Cam and late Evo Sportster)

2017–present (Milwaukee-Eight, Revolution Max, LiveWire)

Quick way to read it: on a '99–'06 bike, V or W is a Twin Cam 88. On '07–'16, a 4 or 5 is a 96 and M or L is a 103. On '17-up, C/D/J/M is a 107, K/P/F is a 114, H/L/Z is a 117, and a 7 is the new 117 in the '24-up baggers. If you see a 1 or S on a new bike, it's a Revolution Max, not a V-twin pushrod motor, and almost nothing on our shelf for Big Twins will bolt to it.

Position 8: Introduction Date and Market

This one changed over the years. Through the 2000s it told you both when in the model year the bike was introduced and which emissions market it was built for. On 2023-up bikes it's just the market.

Position 9: Check Digit

A single digit (or X) that's calculated from the other 16 characters. It doesn't tell you anything about the bike; it's there so a typo or a faked VIN fails the math. If you punch a VIN into a decoder and it says the check digit is wrong, either you mistyped it or something's been altered.

Position 10: Model Year

Letters skip I, O, Q, U and Z so they can't be confused with numbers. The cycle repeats every 30 years, which is why B is both 1981 and 2011. Use the engine code and plant code to tell them apart if it's not obvious.

Position 11: Assembly Plant

Harley changed the plant letters in 2010, so the same letter can mean two different things depending on the year.

Positions 5–6: Model Codes

This is the part that tells you what the bike actually is. Harley reuses two-letter codes across generations, so match the code to the era (position 10). These are the codes you'll actually run into; police, Shrine, sidecar and one-off anniversary variants exist beyond this list.

Touring, 1981–2008

Touring, 2009–present

Softail, 1984–2017 (Evo and Twin Cam)

Softail, 2018–present (Milwaukee-Eight)

Dyna, 1991–2017

FXR, 1982–1994 and 1999–2000

Sportster and Revolution Max

V-Rod (VRSC), 2002–2017

CVO / Screamin' Eagle

Pre-1981 Harleys: No 17-Digit VIN

Before the federal 17-character standard kicked in for 1981, Harley used its own numbering, and it changed a few times.

1970–1980: 9-character frame and engine numbers

Format is two-character model code, five-digit production number, two-character year code. Example: 2A12345H5 is a 1975 FLH. The year codes run H0 = 1970 through H9 = 1979, then J0 = 1980. Common model codes: 1A = XLH Sportster, 2A = FLH, 2C = FLH-80, 3A = XLCH, 4A = FX Super Glide, 4B = FXE, 4C = FXS Low Rider, 5A = FLHS, 6E = FXEF Fat Bob, 6G = FXWG Wide Glide, 9A = FXB Sturgis. Frame and engine numbers should match on an untouched bike.

1962–1969: engine number only

Two-digit year, model letters, four-digit production number: 66FLH1234 is a 1966 FLH. Frames weren't numbered by the factory; the engine number is the identity of the bike. This is the era where title problems and mismatched parts get messy, so check the casting and the stamping font carefully.

1930–1961

Same idea: year, model, sequence, stamped on the left engine case. Model letters were things like EL (61ci Knucklehead), FL (74ci Knuckle / Pan), UL (74ci Flathead), WL (45ci Flathead), G (Servi-Car). Before 1930 only the engine was numbered and before 1910 nothing was.

If you're buying a pre-'81 bike, run the engine number against the title, look for a re-stamp, and if it's a Knuckle or Pan, budget for somebody who knows the cases to look at it.

Want the Computer to Do It?

The free government decoder at vpic.nhtsa.dot.gov runs any 1981-up VIN against the same tables above and will flag a bad check digit. It won't give you accident or title history; for that you need a paid CARFAX or NMVTIS report.

Once you know what you've got, the fitment tab on every product page here filters by exact year and model. If the VIN says '18 FXBB and the seller says it's a '19, believe the VIN.

Shop Harley-Davidson Parts by Model

Questions about a weird VIN or a bike that doesn't decode? Send it over, we've seen most of them.