Anyone buying new rims with a certificate will inevitably come across the KBA number. But what exactly is behind this identifier, where do you find it, and why does it determine whether your rims are legal on the road? This guide tells you everything you need to know about the KBA number for rims – explained clearly and with practical tips.
1. What is the KBA number?
The abbreviation KBA stands for Kraftfahrt-Bundesamt (Federal Motor Transport Authority) – the central authority in Germany responsible, among other things, for the type approval of vehicle parts. If a rim manufacturer wants to launch a new rim, they must have it tested and approved by the KBA. After successful testing, the rim receives a unique KBA number (also called KBA part number).
This number is, so to speak, the "identity card" of your rim. It documents that the component has been tested and meets certain safety requirements. The KBA number can always be used to determine which vehicles the rim is approved for, which tire sizes may be used, and which conditions, if any, apply.
Important: The KBA number alone does not say anything about how the rim was approved. For this, one must distinguish between ABE and parts certificate – more on this below.
Do not confuse: the key numbers in the vehicle registration certificate
A large part of searches for "KBA number" refer to something entirely different, namely the vehicle's key numbers. These are found in registration certificate part I under 2.1 (manufacturer key number, HSN) and 2.2 (type key number, TSN). Both numbers come from the same office but describe different things: HSN and TSN identify your vehicle, while the KBA number on the rim identifies the component.
For the question of whether a particular rim is allowed on your car, you need both sides: the vehicle key numbers to find your model in the vehicle list of the certificate, and the KBA number to even get the correct certificate for the rim. Only if your vehicle appears in the documents for exactly this rim is the combination covered.
How to read HSN, TSN and the other fields is explained in detail in the guide to the vehicle registration certificate.
2. KBA number vs. ABE vs. parts certificate: What's the difference?
Three terms that are often used synonymously, although they mean different things. Here's the clear distinction:
General Operating Permit (ABE)
An ABE is the most comprehensive form of approval. If a rim has an ABE, it means that the rim has been approved by the KBA for certain vehicle types. You receive a multi-page document listing all compatible vehicles with their HSN/TSN numbers. If your vehicle is included, you mount the rim and carry the ABE documents in the vehicle. Registration in the vehicle registration certificate is not required for ABE rims.
Parts Certificate (TGA) according to §19 para. 3 StVZO
A parts certificate is a somewhat more restricted form of approval. It certifies that the rim is fundamentally safe and tested – however, after installation, you must have it registered at an officially recognized testing center. The inspector checks on-site whether the rim is correctly installed, whether there is sufficient clearance in the wheel arch, and whether all conditions of the certificate are met. Only after registration in the vehicle registration certificate is the rim legal.
The KBA number as a link
Both ABE and parts certificates are registered by the KBA and receive a KBA number. This number is therefore not a separate type of approval, but the registration feature. It appears on the ABE document, on the parts certificate, and often directly on the rim itself.
Overview: ABE vs. Parts Certificate
| Criterion | ABE | Parts Certificate |
|---|---|---|
| KBA number available | Yes | Yes |
| Registration required | No | Yes, at testing center |
| Vehicles listed | Yes, in ABE document | Yes, in certificate |
| Effort for owner | Low (carry documents) | Medium (registration required) |
| Legal certainty | High | High (after registration) |
In addition, there is also the individual approval according to §21 StVZO. This is used when neither an ABE nor a parts certificate is available for your vehicle – for example, with imported rims or very unusual combinations. Individual approval is the most complex way, but offers maximum flexibility.
3. Where can I find the KBA number?
The KBA number can appear in various places. Here are the most important locations:
On the rim itself
Many manufacturers stamp or engrave the KBA number directly onto the rim – typically on the inside of the spokes or on the rim flange. The number is often accompanied by other markings such as the manufacturer's logo, size information, and manufacturing date. Sometimes it is difficult to read because it can be covered when mounted.
In the ABE document or parts certificate
Every official certificate contains the KBA number on the first page, usually in the header area or directly under the heading. The number usually has the format "KBA XXXXX" (five digits) or a longer alphanumeric identifier.
From the dealer or manufacturer
Reputable rim dealers provide the KBA number in the item description or supply the certificate directly with the rim. In the zrshop, you receive the corresponding documents – whether ABE or parts certificate – with every rim.
Online with the KBA
The Federal Motor Transport Authority maintains a public register where you can retrieve the associated approval data using the KBA number. This is useful if you are buying used rims and want to check the authenticity of the documents.
4. Do I need to register?
The answer depends on the type of approval your rim has:
No registration required with ABE
If the rim has an ABE (General Operating Permit) and your vehicle is listed in the ABE vehicle list, you do not need to register. You only need to carry the ABE documents in the vehicle. In the event of a traffic stop or a general inspection, you present the document – done.
Registration required with parts certificate
If a parts certificate is available, you must visit an officially recognized testing center after installation. The test engineer checks:
- Correct mounting of the rim (torque, wheel nuts)
- Clearance in the wheel arch (no rubbing during steering or spring compression)
- Compliance with the conditions in the certificate (tire size, ET range)
- No protrusion of the tire beyond the fender edge
After a successful inspection, the change is entered in the vehicle registration certificate (Zulassungsbescheinigung Teil I). Only then is the rim officially approved.
Individual approval for missing documents
If you have rims without an ABE and without a parts certificate – such as imported models – only an individual approval according to §21 StVZO remains. The test engineer then creates an individual certificate for your vehicle. This is the most complex way, but sometimes the only option.
5. What happens without a valid KBA number?
Rims without a valid KBA number and without a certificate are not approved for road traffic in Germany. The consequences can be significant:
Loss of operating permit
Anyone driving rims without valid approval risks the loss of the operating permit according to §19 para. 2 StVZO. This means: Your vehicle is no longer allowed to participate in road traffic until the situation is resolved. In the event of a traffic stop, the vehicle can be impounded.
Fine and points
Unregistered or unapproved rims can lead to fines and points in the driver aptitude register. The exact amount depends on the individual case and the potential danger.
Problems during the main inspection (HU)
During the regular main inspection, the engineer also checks the wheels. Rims without recognizable approval or missing entry in the vehicle registration certificate lead to a significant defect – the HU will not be passed.
Insurance coverage at risk
The most serious point: In the event of an accident with unapproved rims, the motor vehicle insurance may reduce or refuse benefits. While liability insurance pays the injured party, it can claim recourse against the policyholder. Comprehensive insurance may refuse settlement altogether. In the worst case, this means personal liability for the entire damage.
Summary of risks
| Risk | Consequence |
|---|---|
| Operating permit expired | Vehicle is no longer allowed to drive |
| Traffic stop | Fine, points, possible impoundment |
| HU not passed | Re-inspection required |
| Accident with fault question | Insurance may reduce/refuse benefits |
6. Do original rims have a KBA number?
This is one of the most common questions, and the answer is usually: no, and they don't need one. Wheels supplied ex works with the vehicle are part of the vehicle's type approval. They are therefore covered by the car's operating permit and do not require their own ABE. Instead of a KBA number, they usually bear a part number of the vehicle manufacturer, often together with size information, offset, and manufacturing date on the inside or behind the spokes.
Which wheel-tire combinations are approved for your vehicle ex works can be found in the vehicle registration certificate part I in field 15 and, for supplementary approvals, in the remarks under field 22. For newer vehicles, the complete list is found in the CoC certificate.
The case that is often overlooked
It becomes tricky when original rims from a different model are mounted, for example, a factory rim from a more powerful series or from a different year of manufacture. This combination is not automatically co-approved just because both wheels come from the same manufacturer. Without an entry in the vehicle documents, you need a parts certificate or an individual approval according to § 19 para. 2 and 3 StVZO, just like with an accessory rim.
For used factory wheels, this practically means: note down the part number, check with the authorized dealer or using the vehicle documents whether the size is approved for your variant, and in case of doubt, ask a testing organization before mounting. A missing KBA number is not a defect for original wheels, but a missing proof of assignment is.
7. Rims with ABE and certificate in the zrshop
At zrshop, we attach great importance to ensuring that every rim is supplied with the appropriate documents. Whether ABE or parts certificate – you always receive the complete documents so that you are on the safe side.
Our brands such as DEZENT and Tomason are known for wide vehicle coverage in their ABE lists. This means: For most common vehicles, no separate registration is required – mount the rim, carry the ABE, done.
What you should pay attention to when buying
- KBA number available: Every reputable rim has a KBA number. If it's missing, keep your hands off.
- Vehicle listed in ABE: Before buying, check whether your vehicle (HSN/TSN) is in the approval list.
- Observe conditions: Even for ABE rims, conditions may apply – such as specific tire sizes or centering rings.
- Check dimensions: In addition to the certificate, bolt pattern, offset, and load capacity must match the vehicle.
- Keep documents: Place a copy of the ABE or certificate in the glove compartment and store the original securely.
Discover rims with certificates in the zrshop now →
FAQ: Frequently asked questions about the KBA number for rims
What is a KBA number for rims?
The KBA number is a registration number issued by the Federal Motor Transport Authority, which documents that a rim has been tested and approved. It can be found on the certificate (ABE or parts certificate) and often directly on the rim.
Is the KBA number the same as an ABE?
No. The KBA number is the registration number assigned to both an ABE and a parts certificate. The ABE is the type of approval – the KBA number is the corresponding identifier in the register of the Federal Motor Transport Authority.
Where can I find the KBA number on my rim?
The KBA number is usually engraved or embossed on the inside of the rim – typically on a spoke or the rim flange. Additionally, it is always on the supplied ABE document or parts certificate.
Do I need to register rims with ABE?
No. Rims with ABE do not need to be entered in the vehicle registration certificate, provided your vehicle is listed in the ABE vehicle list. You only need to carry the ABE documents in the vehicle.
What happens if my rims don't have a KBA number?
Rims without a KBA number and without other approval (e.g., ECE marking) are not approved for road traffic in Germany. Driving with such rims can lead to the loss of the operating permit, fines, and problems with insurance.
Can rims have both ABE and parts certificates?
Yes, that happens. Some rims have an ABE for a wide range of vehicles, and additionally a parts certificate for vehicles not covered in the ABE. This ensures compatibility for as many models as possible.
Do original rims have a KBA number?
Mostly not, and they don't need one. Wheels fitted ex works are covered by the vehicle's type approval and carry a part number of the vehicle manufacturer instead of a KBA number. The situation is different for factory rims from another model: these are not automatically co-approved.
Is the KBA number the same as HSN and TSN in the vehicle registration certificate?
No. HSN (Field 2.1) and TSN (Field 2.2) identify the vehicle, while the KBA number identifies the component, i.e., the rim. For an approval check, you need both.
Sources
- Federal Motor Transport Authority (KBA) – Information on type approvals and vehicle component registration
- Road Traffic Licensing Regulations (StVZO) – §19, §21, §22