The short answer first: The HSN (manufacturer's key number) is located in Field 2.1 of Registration Certificate Part I and consists of four digits. The TSN (type key number) is located directly next to it in Field 2.2; its first three characters are the actual key number. In the old, grey vehicle registration document, you will find both under points "zu 2" and "zu 3". Together, these two numbers uniquely identify your vehicle, which is precisely why they appear wherever the exact model is important: for car insurance, for spare parts, and in the vehicle lists of rim expert opinions.
Note: This guide explains the key numbers based on the German registration certificate. For imported vehicles or individual approvals, the entries may differ, more on this below. What is stated in your own documents is always binding.
1. What HSN and TSN actually are
Behind the two acronyms is a system of the Federal Motor Transport Authority (KBA). The HSN is a four-digit number permanently assigned to each vehicle manufacturer. The TSN describes the specific type from this manufacturer, i.e., the combination of model, engine, and body. Only the pair of both numbers is unique: the HSN alone only says who built the vehicle, the TSN alone is useless without the manufacturer, because different manufacturers can assign the same type keys.
The numbers are assigned as part of type approval. As soon as a vehicle type is approved for the German market, it receives its key, which is then transferred to every registration certificate of that type. For you, this means: Two vehicles with an identical HSN/TSN combination are the same type from the point of view of registration, even if the color and equipment are different.
You should not confuse the key numbers with the Vehicle Identification Number (VIN) in field E. The 17-digit VIN identifies your individual vehicle, like a fingerprint: No second car in the world has the same. HSN and TSN, on the other hand, describe the type, which exists a thousand times over. That's why the insurance company asks for the key numbers (they want to classify the type), while workshops and manufacturers need the VIN for recalls or spare parts with build-status relevance (they want your specific vehicle). For rim vehicle lists, the type, i.e., the key pair, is sufficient.
2. Where to find HSN and TSN
In Registration Certificate Part I (the "vehicle registration document", issued since October 2005), both numbers are at the top of the document:
| Document | HSN | TSN |
|---|---|---|
| Registration Certificate Part I | Field 2.1 (four digits) | Field 2.2 (first three characters) |
| Old Vehicle Registration Document (before October 2005) | Point "zu 2" | Point "zu 3" (first three digits) |
| Registration Certificate Part II | Field 2.1 | Field 2.2 |
Two practical stumbling blocks: Field 2.2 often contains more than three characters. The actual TSN consists of the first three; what comes after that are additional keys for variant and version. And in the old grey vehicle registration document, line "zu 3" is longer than three digits; there, too, only the first three digits count. If a form asks for "HSN/TSN", this exact pair is almost always meant: four digits plus three characters.
Good to know: Registration Certificate Part I is the document that must be carried when driving, so you usually have the key numbers with you in the vehicle. Part II (the former vehicle title), on the other hand, should be kept securely at home, as it is proof of ownership. For a quick query on the go, a photo of the relevant fields on your phone is sufficient, so you don't have to rummage through the glove compartment every time you compare insurance.
A detailed overview of all fields in the registration certificate, from unladen weight to power, can be found in our guide Vehicle Registration Document Explained.
3. How the numbers are structured
The HSN is purely numeric and always four digits long. Some known examples (as of 2026, assigned by the KBA):
| HSN (Example) | Manufacturer |
|---|---|
| 0005 | BMW |
| 0588 | Audi |
| 0603 | Volkswagen |
| 1313 | Mercedes-Benz |
Important: Over the decades, large manufacturers have sometimes received multiple HSNs, for example due to factory locations, company name changes, or corporate brands. It is therefore completely normal if your VW has a different HSN than your neighbor's VW. A list from the internet is never authoritative; the entry in your documents is.
Since the changeover to the registration certificate, the TSN has been alphanumeric, meaning letters and numbers can occur (for example, "ABC" or "429"). If a model changes technically relevantly, for example due to a new engine variant, the new variant usually also receives its own TSN. Therefore, two outwardly identical cars of the same model year can have different type keys.
To read this in plain text, using an excerpt marked as an example: If field 2.1 contains the value "0603" and field 2.2 contains the value "BJX00151", then your answer to any HSN/TSN query is "0603 / BJX". The HSN says "Volkswagen", the three characters "BJX" name the type, and the five characters after that describe the variant and version, which you usually don't need for insurance and expert opinions. If you are unsure when reading, simply compare the field numbers: they are printed in small type directly next to the values, and in the same place on every registration certificate.
4. What you need HSN and TSN for
The key numbers are the fastest way to uniquely identify a vehicle without typing out the 17-digit vehicle identification number. The three most common applications:
Car insurance: When taking out insurance, every insurer asks for HSN and TSN, because these determine the type classes for liability, partial, and comprehensive insurance. The type classes are recalculated annually from the claims record of the respective vehicle type, and this record is assigned precisely via the key pair. With the numbers, your vehicle is precisely determined, typos in model names no longer play a role, and two engine variants of the same model can cost completely different premiums because they have different type keys and thus their own claims statistics.
Spare parts and accessories: Anyone buying brakes, chassis, or wheels needs to know for which vehicle exactly. Many catalogs and workshop systems internally use key numbers because they are more precise than any model designation.
Rims and expert opinions: This is where the numbers become really important for you as a rim buyer. The vehicle lists in parts certificates and ABE documents often list the approved vehicles with their key numbers. If you want to know if a rim is approved for your car, you simply compare the HSN and TSN from your registration document with the list in the expert opinion. If both match, you are on the list; if they don't match, even a "but it's the same model" argument won't help, because for the inspection body, the type key counts.
Such a vehicle list is usually structured as a table: one column for the HSN, one for the TSN (often several TSNs per line, if many engine variants are approved), plus trade designation, permissible tire sizes, and the condition codes, whose meaning is explained at the end of the expert opinion. Always read the entire line for your key: It can happen that a type is approved, but only with certain tire dimensions or with conditions such as a modification inspection. The key numbers thus lead you to the correct line, and the line itself then provides the conditions.
Find rims for your vehicle: to the rim configurator
5. From the key number to the right rim
At zrshop, you select your vehicle in the configurator by make, model, year of manufacture, and engine type. These details are most reliably read from the vehicle registration document, and the key numbers help you rule out confusion: If you are unsure about the generation or engine variant, the TSN, in combination with the performance data in the registration document, will tell you which version you are actually driving.
A typical example from our consulting: A compact model is offered in two generations parallel for years, so the year of manufacture alone is not enough to distinguish them. If you then choose the wrong generation in the configurator, you will be shown rims with an unsuitable bolt circle or incorrect offset. Comparing the TSN and performance (field P.2) with the seller's information or the model history rules out precisely this confusion before any money changes hands.
Once you have identified your vehicle, the technical data then determine the fit: the bolt pattern, the offset, and the wheel load. All three values depend on the vehicle type, and thus ultimately again on what HSN and TSN describe. And whether a specific rim has an approval for your type is clarified by looking at the expert opinion, whose numbering system we explain in the guide to the KBA number for rims.
Do not confuse: The KBA number on a rim identifies the component, i.e. the rim itself. HSN and TSN identify the vehicle. Both systems originate from the same office, but describe completely different things, and only together do they provide the answer to the question "does this rim legally fit my car?".
6. Special cases: Import, classic cars, modified vehicles
Not every vehicle on German roads has a "speaking" key number. For imported vehicles without German type approval, such as US models that have been registered through individual approval, the fields may be filled differently. In such cases, the information from the individual approval or the EC certificate of conformity (CoC) applies, and for rims, the path practically always leads through an assessment of the specific combination by an officially recognized inspection body.
For older vehicles with a grey vehicle registration document, the above applies: HSN under "zu 2", TSN under "zu 3". The numbers themselves remain the same over the years; a change of document does not change the key. And for modified vehicles, for example after an engine conversion with individual acceptance, the type key still describes the original type; what is actually installed and entered is then found in the remarks fields of the registration certificate. Our guide Registering rims successfully with TÜV shows how such an entry works.
7. Registration document not at hand? How to still get the numbers
Sometimes you need the key numbers precisely when the registration certificate is not readily available. These paths will still lead you to your goal:
Insurance documents: Your policy or annual premium statement almost always includes the HSN and TSN, as the insurer used them to classify your vehicle. The numbers are also available in the customer portal of many insurers in the contract data.
Purchase documents and CoC: For a new car, the EC certificate of conformity (CoC) is included, which fully describes the approved type. Purchase agreements or vehicle valuations also often list the key numbers.
Registration office: As the owner, you can view your vehicle's data there at any time or apply for a replacement registration certificate if the original is lost.
Anyone looking for an HSN/TSN database to look up key numbers without their own documents has two reputable sources: The Federal Motor Transport Authority publishes the official list of manufacturer and type key numbers as a retrievable directory, and many car insurers offer a vehicle search in their tariff calculators that translates model selections into key numbers. Both are suitable for looking up and cross-checking; for the binding answer as to which numbers YOUR vehicle carries, your own registration certificate remains the only source, because especially with several engine variants of the same model, a database search can quickly suggest the wrong line.
We advise against pure online queries via license plates or model names for binding purposes: Such databases are third-party offerings whose status you cannot verify. For the question of whether a rim is approved, ultimately only the pair from your own document counts.
FAQ about HSN and TSN
Where are HSN and TSN located in the vehicle registration document?
In Registration Certificate Part I, in Field 2.1 (HSN, four digits) and Field 2.2 (TSN, the first three characters). In the old grey vehicle registration document, they are under "zu 2" and "zu 3".
Is the TSN always three digits long?
The actual TSN consists of three characters. In field 2.2, further characters may follow, describing the variant and version of the type. If a form asks for the TSN, the first three characters are meant.
What is the difference between HSN/TSN and a rim's KBA number?
HSN and TSN identify your vehicle; the KBA number identifies the rim as a component. To determine if a rim is approved for your car, you need both: the rim's expert opinion lists the approved vehicles, often precisely via their HSN/TSN.
Can two identical models have different key numbers?
Yes. Different engine types, body styles, or model facelifts of the same model receive their own type keys, and large manufacturers sometimes have multiple HSNs. The entry in your own documents is always binding.
Do HSN and TSN change when the owner changes?
No. The key numbers describe the vehicle type, not the owner. They remain the same across sales, re-registrations, and new documents, as long as the vehicle technically corresponds to the approved type.