The vehicle registration certificate – officially Registration Certificate Part I – is full of codes and abbreviations that can be confusing at first glance. Yet, it contains all the important data of your vehicle: from the HSN/TSN to HP and kW, and the factory-approved tire size. Especially when buying rims and tires, this certificate is your most important source. In this detailed guide, we explain every relevant field – clearly and with practical relevance.
1. Vehicle registration certificate or Registration Certificate Part I?
Both terms refer to the same document. Since October 1, 2005, the former vehicle registration certificate is officially called Registration Certificate Part I (ZBI for short). However, the old name has stuck in everyday use – when someone refers to the "vehicle registration certificate," they almost always mean the ZBI. It must be carried while driving and contains the technical data as well as the registration data of the vehicle.
Vehicle registration certificate vs. vehicle title
The ZBI should not be confused with the Registration Certificate Part II (formerly vehicle title). The difference:
- Registration Certificate Part I (vehicle registration certificate): carried in the vehicle, contains the technical data – this is the certificate you need when buying rims.
- Registration Certificate Part II (vehicle title): the proof of ownership, which you keep at home and need for selling the vehicle.
2. Overview of the most important fields
The fields of the ZBI are uniformly marked throughout the EU with letters and numbers (codes). This table shows the most important ones at a glance:
| Field / Code | Meaning |
|---|---|
| A | Official license plate |
| B | Date of first registration |
| 2.1 | Manufacturer code (HSN) |
| 2.2 | Type code (TSN) |
| 3 / E | Vehicle Identification Number (VIN) |
| D.1 / D.2 / D.3 | Make / Type, Variant, Version / Commercial Description |
| G | Mass in running order (curb weight) |
| F.1 / F.2 | Technically permissible / Permissible maximum mass |
| J | Vehicle class |
| P.1 | Engine displacement (cm³) |
| P.2 | Rated power (kW) |
| P.3 | Fuel type |
| 7.1 / 8.1 | Permissible axle loads (technical / in operation) |
| K | Type approval number |
| Q | Power-to-weight ratio (kW/kg) |
| S.1 | Number of seats |
| T | Maximum speed (km/h) |
| V.7 / V.9 | CO₂ value / Emission class |
| 15.1 / 15.2 | Tires (permissible tire sizes) |
| 22 | Remarks and exceptions |
Not every field is relevant to everyone. For buying rims and tires, you primarily focus on fields 2.1/2.2 (HSN/TSN), 15 (tire size), and the masses/axle loads (F and 7/8). The remaining fields concern the engine, environment, and registration.
3. HSN and TSN: the key numbers (Field 2.1 and 2.2)
The key numbers are the most important part of the entire certificate for buying rims – they allow your vehicle to be uniquely identified:
- HSN (Manufacturer Code): four-digit number in Field 2.1. It stands for the vehicle manufacturer (e.g., a specific number for Volkswagen).
- TSN (Type Code): three-digit letter/number combination in Field 2.2. It designates the specific vehicle type, including variant and version.
Together (HSN + TSN), they identify your vehicle so precisely that it can be determined which rims and tires are approved. This is exactly why rim shops and ABE lists ask for these numbers. In older vehicle registration certificates, you will find the HSN under "zu 2" and the TSN under "zu 3".
Why HSN/TSN is crucial for finding rims
Every rim with an ABE has a list of approved vehicles – and this list is based on HSN/TSN. If you provide your key numbers, it can be immediately checked whether a rim fits your vehicle without requiring registration. Ideally, this saves you a trip to the inspection center. You can find more information on this in the guide KBA number for rims.
For example: Two vehicles of the same model can have different TSNs depending on the engine, year of manufacture, and equipment – and thus different rim approvals. That's why it's not enough to simply state "VW Golf"; only HSN and TSN make the assignment unambiguous. You can only find the key numbers in the vehicle registration certificate (ZBI) – not on the vehicle itself. So, keep the certificate ready when buying rims.
4. HP and kW in the vehicle registration certificate (Field P.2)
The engine power is in Field P.2 – but in kilowatts (kW), not horsepower (HP). You can easily convert it:
- kW to HP: kW × 1.36 (more precisely: × 1.35962)
- HP to kW: HP ÷ 1.36
Example: 110 kW corresponds to approximately 150 HP. The HP value itself is not in the certificate – you calculate it from the kW number in Field P.2. The corresponding engine displacement in cm³ is in Field P.1, and the fuel type is in Field P.3.
5. Curb weight and maximum permissible mass (Field G, F.1, F.2)
The curb weight – officially "mass of the vehicle in running order" – is in Field G. The maximum permissible mass is listed separately:
- Field F.1: technically permissible maximum mass.
- Field F.2: maximum permissible mass in the registration state.
These values are indirectly important when buying rims: The permissible axle load determines the minimum load capacity that the rim and tire must have – especially for heavy vehicles, SUVs, and vans. More on this in the guide Load index for tires.
Axle loads (Fields 7 and 8)
In addition to the total mass, the certificate specifies the permissible axle loads per axle: the technically permissible values are in fields 7.1, 7.2 (etc.), and the values permissible in operation are in 8.1, 8.2. These specifications are particularly informative for tires and rims: If you divide the permissible axle load by two, you get the load per wheel – and from that, the minimum required load capacity of the tire and rim. Especially for vans and motorhomes with high rear axle loads, this is the decisive value when choosing wheels and tires.
6. First registration and year of manufacture (Field B)
Field B contains the date of first registration. Important: This is not necessarily the year of manufacture – a vehicle may have been built somewhat before its first registration. A separate "year of manufacture" is not specified in the vehicle registration certificate; the first registration serves as a guide. The exact production date can only be determined by the manufacturer using the VIN.
7. Tire size in the vehicle registration certificate (Field 15)
For tires and rims, Field 15 (with subfields 15.1, 15.2, sometimes 15.3) is particularly important: This is where the factory-approved permissible tire sizes are listed, including tire size, load, and speed index. A typical entry looks like this:
205/55 R16 91V – where 205 means the tire width in mm, 55 the aspect ratio, R the radial construction, 16 the rim diameter in inches, 91 the load index, and V the speed index.
Often, several sizes are listed in field 15 (15.1, 15.2, sometimes 15.3) – for example, a narrower winter dimension and a wider summer dimension. All sizes mentioned there may be driven without further registration. If your desired size is not in the certificate, it is not automatically prohibited: the ABE or the parts certificate of the rim may approve further combinations.
Therefore, not every permissible size needs to be listed in the certificate. The guide Rim width and tire width explains how rim width and tire width relate; the meaning of offset and bolt pattern can be found in the respective guides.
8. Vehicle Identification Number (VIN, Field E)
The VIN (Vehicle Identification Number, colloquially chassis number) is a 17-digit code that uniquely identifies every vehicle worldwide. It is found in Field E (and additionally as Field 3). Through the VIN, exact equipment and production data can be determined from the manufacturer. It is also stamped on the vehicle itself.
9. Other frequently sought fields
- Vehicle class (Field J): e.g., M1 for passenger cars, N1 for light commercial vehicles.
- Make, Type, Commercial description (D.1/D.2/D.3): Manufacturer and model description in plain text.
- Remarks and exceptions (Field 22): This section lists registered modifications – such as retrospectively approved rims with conditions.
10. New and old vehicle registration certificate
Vehicles registered before October 2005 often still have the old vehicle registration certificate (unless it has been replaced in the meantime). The content is the same, only the structure and field designations differ:
- In the old certificate, the HSN is under "zu 2" and the TSN under "zu 3"; the fields do not have EU codes.
- In the new Registration Certificate Part I, the fields are EU-uniformly coded with letters/numbers (e.g., 2.1, 2.2, P.2, G).
Both lead to the goal when buying rims – you just need to know where the HSN/TSN and tire size are located in each. If an old document is reissued (e.g., due to a change of owner or loss), you automatically receive the new registration certificate.
11. Lost vehicle registration certificate or change of ownership
If the vehicle registration certificate is lost or stolen, the registration office will issue a replacement ZB I upon presentation of an ID and the vehicle title (Registration Certificate Part II). In the event of a change of ownership or relocation, the owner data will be updated; the technical data (and thus HSN/TSN, tire size) remain unchanged. Important: Always carry the original certificate with you – a copy is not sufficient during a check.
12. How to find the right rims with your vehicle registration certificate
For buying rims, you primarily need three pieces of information from your certificate:
- HSN/TSN (Fields 2.1 and 2.2) – to check which rims are approved.
- Tire size (Field 15) – as a starting point for suitable wheel-tire combinations.
- Total mass/axle load (Field F) – for the necessary load capacity.
With this data, you can quickly find rims and complete wheels in the zrshop that match your vehicle – ideally with an ABE, so no registration is necessary. If a combination is not approved ex works, the guide How to successfully register rims with TÜV can help.
In summary: The vehicle registration certificate seems complicated but is quickly deciphered if you know the most important fields. For tires and rims, HSN/TSN, tire size, and permissible masses are crucial. Anyone with these three pieces of information at hand will find suitable wheels without unpleasant surprises – and will immediately know whether registration is required or not.
Discover suitable rims in the zrshop now →
FAQ: Frequently asked questions about the vehicle registration certificate
Where can I find the HSN and TSN in the vehicle registration certificate?
The HSN (Manufacturer Code) is in field 2.1, the TSN (Type Code) in field 2.2 of Registration Certificate Part I. In older vehicle registration certificates, you will find the HSN under "zu 2" and the TSN under "zu 3".
Where is the power (HP) in the vehicle registration certificate?
The rated power is in field P.2, but in kilowatts (kW). You calculate the HP number by multiplying kW × 1.36 – so 110 kW corresponds to approximately 150 HP. There is no direct HP specification in the certificate.
Where is the engine displacement in the vehicle registration certificate?
The engine displacement in cubic centimeters (cm³) is in field P.1. You will find the fuel type directly below it in field P.3.
Where is the curb weight?
The curb weight – the mass of the vehicle in running order – is in field G. The permissible total mass is listed separately in fields F.1 and F.2.
Is the first registration the same as the year of manufacture?
Not necessarily. Field B states the date of first registration; the year of manufacture may be somewhat earlier. A separate year of manufacture is not stated in the certificate – the exact production date can only be determined by the manufacturer using the VIN.
What tire size am I allowed to use?
The factory-approved tire sizes are listed in field 15 (15.1, 15.2). Additional sizes may be approved by the ABE or the parts certificate of the rim. Besides the width, the load index and speed rating are also important.
What is the difference between a vehicle registration certificate and a vehicle title?
The vehicle registration certificate (Registration Certificate Part I) is carried in the vehicle and contains the technical data. The vehicle title (Registration Certificate Part II) is proof of ownership and is kept at home.
What is the key number in the vehicle registration certificate?
"Key number" usually refers to HSN and TSN – the manufacturer and type code numbers in fields 2.1 and 2.2. Together, they uniquely identify your vehicle and are the key to finding suitable rims.
Can I order rims with the vehicle registration certificate?
Yes. With HSN/TSN (Field 2.1/2.2), you can check which rims are approved for your vehicle, and the tire size (Field 15) serves as a starting point for suitable combinations. This allows you to quickly find rims and complete wheels that match your vehicle.
What does field 22 in the vehicle registration certificate mean?
Field 22 contains "Remarks and exceptions" – i.e., registered modifications to the vehicle. This includes, for example, retrospectively approved rims with the associated conditions. A look at this field shows what modifications have already been entered.
Sources
- Vehicle Registration Ordinance (FZV) – Registration Certificate Part I and II
- EU-uniform coding of fields (harmonized community codes) of the registration certificate
- Federal Motor Transport Authority (KBA) – Key numbers HSN/TSN