Finding the VIN: where the chassis number appears and how to check it properly

What the VIN is and why it matters so much

The VIN is your vehicle's unique identifier — comparable to a fingerprint or an ID number. Officially it is called the Fahrzeug-Identifizierungsnummer (FIN, vehicle identification number) in German; internationally it is known as the Vehicle Identification Number (VIN). Both terms mean the same thing: a globally unique string of characters that identifies exactly one vehicle. Unlike the number plate, which changes with every re-registration, the VIN stays the same over the entire lifetime of the vehicle.

When buying a used car, the VIN is central for two reasons. First, it links the actual lump of metal in front of you with the papers: only when the number on the vehicle exactly matches the number in the documents do you have certainty that the papers and the car belong together. Second, the VIN is the key to almost all further information — from ordering spare parts to open recalls and the vehicle history. Anyone who doesn't check the VIN forgoes the single most important anchor of the entire document check.

A clean distinction from the other codes in the vehicle registration matters here: the HSN (Herstellerschlüsselnummer, manufacturer key number) and TSN (Typschlüsselnummer, type key number) in fields 2.1 and 2.2 identify the vehicle type, not the individual vehicle. The engine code letter is something completely different too, and is covered in the sister article on the engine code. The VIN is the only entry that sets your specific example apart from every other identically built vehicle.

Where the VIN appears in the vehicle registration

In the vehicle registration — the Zulassungsbescheinigung Teil 1 (registration certificate part 1) — you'll find the VIN in field E. Since the EU-wide harmonisation, the fields of the registration certificate are marked with letters and numbers, and field E is reserved for the vehicle identification number. The field sits in the upper part of the document, usually right next to the fields for the manufacturer (D.1) and type. What exactly the other fields contain is explained by the sister article on understanding the registration and the full field-code legend — here we only deal with field E.

The same VIN is also entered in the Zulassungsbescheinigung Teil 2 (registration certificate part 2), the former Fahrzeugbrief (vehicle title). Part 2 is handed over on sale, but it is not proof of ownership — the details on that and on the ownership question are covered in the sister article on part 2. For the pure VIN check, the rule is: the number must be identical in part 1 and part 2. If it differs between the two documents, that is a serious warning sign — the papers may not belong together, or one of them may be forged.

A practical note on reading it: the 17 characters of the VIN are usually printed on the paper as a continuous string without spaces. Take your time and read them character by character. Especially with small print or worn documents, it pays to read the number out loud as you go, or to photograph it, so you can calmly match it against the vehicle later. One feature helps here: a VIN never contains the letters I, O and Q, because they could be confused with the digits 1 and 0. So if you think you're reading an O or an I, it is almost always a zero or a one.

Where to find the VIN on the vehicle

On the vehicle itself, the VIN is deliberately placed in several locations — this makes tampering harder and helps you with the match. You should know all the key locations when buying a used car and check as many of them as possible.

In the engine bay, stamped into the metal: The most original and forgery-proof version is the number stamped or pressed directly into a load-bearing body panel. Depending on the manufacturer, you'll find it on the strut tower, the side member, the bulkhead or under a cover in the engine bay. This stamping sits in the metal of the body and cannot be changed without effort — which is precisely why it is so meaningful.

Viewing window at the bottom of the windscreen: On almost all modern vehicles, the VIN is readable from outside through a small viewing window in the dashboard, visible through the windscreen, usually at the bottom left on the driver's side. So you can read it from outside without opening the door. This spot is handy for a quick first check.

Door pillar and door frame: If you open the driver's door, you'll often find a sticker or plate on the B-pillar or the door frame carrying the VIN and further vehicle data such as tyre pressure and paint code. A corresponding entry may additionally be present on the passenger side.

Type plate: The type plate — a small metal or plastic plate, usually riveted in the engine bay or door area — carries the VIN together with manufacturer details and the permissible weights. Pay close attention to how it is fixed: an originally riveted type plate sits firmly and shows even, aged rivets. A freshly riveted or glued-on plate on an older vehicle is conspicuous and warrants a closer look. The weight figures on the type plate itself are covered by the sister article on weights and payload.

Understanding the 17 characters of the VIN

A valid VIN always consists of exactly 17 characters — a combination of capital letters and digits, but without I, O and Q. These 17 positions are not arbitrary; they are structured into three blocks according to an international standard. You don't have to decode the VIN yourself, but a rough understanding helps you assess plausibility and anomalies.

Block	Positions	Name	Content
WMI	1–3	World Manufacturer Identifier	World manufacturer code (country and brand)
VDS	4–9	Vehicle Descriptor Section	Vehicle description (model, body, engine, etc.)
VIS	10–17	Vehicle Identifier Section	Individual part, often with model year and serial number

The first block, the WMI, reveals the manufacturer and the region of origin. Vehicles from Germany, for example, often begin with a W, vehicles from other regions with other opening characters. The WMI is manufacturer-bound and can be roughly cross-checked against the brand of the vehicle — if the paper states a German brand but the WMI clearly doesn't fit, a second look is worthwhile.

The middle block, the VDS, describes the vehicle technically: model series, body shape, sometimes the engine and equipment features. Exactly how these positions are assigned is defined by each manufacturer in its own scheme. The last block, the VIS, is the individual part. With many manufacturers it contains, at a certain position, a code for the model year as well as a running production number that makes the individual example unique. An important distinction: the model year that can be read from the VIN is not the same as the year of manufacture or the first registration — that distinction is covered by the sister article on determining the build year.

The buyer's core: matching the VIN — character by character

This is the most important check step and the actual reason you're looking for the VIN in the first place. Take the VIN from the vehicle registration (field E) and compare it character by character with the number on the vehicle. Don't skim it — go through each of the 17 positions individually: first position with first position, second with second, and so on. While doing so, match as many locations on the vehicle as possible — the viewing window at the windscreen, the stamping in the engine bay and the type plate. All must show the same number as the papers.

Why this effort? Because a discrepancy is one of the most serious warning signs of all. If the number on the vehicle doesn't match the one in the papers, it can mean that the papers belong to a different vehicle, that a stolen vehicle is being sold with the documents of a legal one (so-called re-plating or cloning), or that the identity of the vehicle has been tampered with. In all of these cases you should walk away from the deal — no matter how convincing the seller appears.

When looking at the stamped locations on the vehicle, also pay attention to the condition of the characters themselves. Originally stamped VIN characters are evenly deep, cleanly aligned and stamped at equal spacing. Warning signs are: subsequently stamped or re-punched characters that look out of line; ground-down, filled or over-painted areas around the stamping; different fonts within the same number; and a surface that looks fresher, smoother or inappropriately treated compared with the surrounding metal. A type plate that has visibly been newly riveted or glued on also falls into this category. Such traces point to a deliberate alteration of the vehicle identity.

The VIN check is closely related to uncovering other forms of tampering, but it is not the same. Odometer fraud is about the mileage; the VIN is about the identity of the vehicle — how to spot a manipulated mileage reading is covered in the sister article on odometer fraud. For the VIN, the rule is: take the two or three minutes for the character-by-character match. It is one of the few check steps that require no technical knowledge whatsoever and still rule out a catastrophic risk.

What else you need the VIN for

Beyond the identity match, the VIN is the universal key to information about the vehicle. Anyone who knows it can research in a targeted way before buying — and later save time and money in everyday life.

Spare parts: When ordering spare parts, the VIN is often the most reliable basis. It can be used to determine the exact vehicle configuration, so that the workshop or parts dealer can uniquely assign the matching component — particularly for vehicles that have undergone technical changes over the model's production run. This saves expensive wrong purchases and returns.

Recalls: Manufacturers organise recall campaigns and technical service measures on a per-vehicle basis. With the VIN you can have it checked whether open recalls exist for a specific vehicle and whether earlier recalls have already been carried out. A vehicle with an outstanding safety-relevant recall is a solid negotiating point — and a reason to insist that it be dealt with before you take delivery.

History and ownership enquiry: The VIN is the basis for vehicle-history reports (VIN reports) that compile reported events such as roadworthiness tests with mileage, reported accidents or registration history. However, such reports only capture reported events and are not complete proof — their possibilities and limits are put into perspective in detail by the sister article on odometer fraud. For all of these searches you need the exact VIN — another reason to read it off and note it down cleanly.

When you want certainty during the check

The character-by-character match of the VIN between paper and vehicle is one of the few check steps that anyone can carry out themselves without tools or expert knowledge — and you should do it consistently at every used-car purchase. Assessing finer signs of tampering, however, is more demanding: whether a stamping has been re-punched, whether a metal area around the VIN has been ground down or a type plate swapped out is spotted far more reliably by a trained eye than by a layperson under time pressure at the viewing appointment.

checkdenwagen makes matching the VIN between registration certificate part 1, part 2 and the stamped locations on the vehicle a fixed part of the identity and document check. The inspector checks the relevant locations, assesses the stamping and the type plate for signs of tampering, and puts anomalies into perspective objectively. The findings are documented in the written photo report — part of an on-site check with over 100 points, available Germany-wide from €289 incl. VAT and travel. The Premium package adds a market-value assessment as a basis for the price negotiation.